Я должен установить эти пакеты Помощника Ubuntu?

Просто узнайте, содержат ли они что-либо интересное для Вас самих при помощи командной строки:

• Прочитать общее описание пакета и прямые зависимости и рекомендуемый (автоматически установленный также) пакеты:

  apt show PACKAGENAME 
  

• Для обнаружения точно, что произошло бы, если Вы устанавливаете его (например, который другие пакеты будут установлены как зависимости):

  apt install --simulate PACKAGENAME
  

Вот важные части apt show выводы для Вас:

mate-desktop-environment:

 This package installs the standard set of applications that are
 part of the official MATE release.
 .
 It also suggests a few non-MATE standard desktop applications like an
 internet browser, a mail reader and a network management applet.

Это установит пакеты atril, desktop-base ИЛИ ubuntu-wallpapers, engrampa, eom, ffmpegthumbnailer, galculator, mate-applets, mate-icon-theme-faenza, mate-media, mate-notification-daemon, mate-power-manager, mate-screensaver, mate-system-monitor, mate-themes, mate-user-guide, mate-utils, pluma

mate-desktop-environment-extra:

 Depends: mate-desktop-environment-extras (= 1.12.0+1)
 [...]
 This package (mate-desktop-environment-extra) is a dummy package and can be
 safely removed.

Таким образом, единственная цель этого пакета состоит в том, чтобы установить mate-desktop-environment-extras - это - только имя псевдонима, если Вы хотите назвать его как этот.

mate-desktop-environment-extras:

 This package installs an extra set of MATE components that are
 also part of the official MATE release.

Это установит пакеты blueman, caja-gksu, caja-image-converter, caja-open-terminal, caja-sendto, caja-share, caja-wallpaper, dconf-editor, gnome-keyring, mate-gnome-main-menu-applet, mate-netspeed, mate-sensors-applet, mate-user-share, mozo, yelp

ubuntu-mate-desktop:

Description: Ubuntu MATE - full desktop
 This package is the Ubuntu MATE desktop environment.
 .
 It is safe to remove this package if some of these packages are not desired.

Это установит эти пакеты:

a11y-profile-manager-indicator
account-plugin-facebook
account-plugin-flickr
account-plugin-google
accountsservice
acpid
alsa-base
alsa-utils
anacron
apport
apport-gtk
apport-symptoms
apturl
at-spi2-core
atril
avahi-autoipd
avahi-discover
avahi-dnsconfd
avahi-utils
bc
blueman
brasero
brasero-cdrkit
brltty
brltty-x11
ca-certificates
caja
caja-gksu
caja-open-terminal
caja-sendto
caja-wallpaper
cheese
colord
compiz
compiz-core
compiz-mate
compiz-plugins
compiz-plugins-default
crda
cups-browsed
cups-core-drivers
cups-filters-core-drivers
cups-pk-helper
cups-ppdc
dconf-cli
dconf-editor
deja-dup
deja-dup-backend-cloudfiles
deja-dup-backend-gvfs
deja-dup-backend-s3
deja-dup-caja
dialog
dmz-cursor-theme
engrampa
eom
espeak
ethtool
exfat-fuse
exfat-utils
ffmpegthumbnailer
firefox
folder-color-caja
fonts-dejavu-core
fonts-freefont-ttf
fonts-liberation
fonts-nanum
fonts-noto
fonts-noto-cjk
fonts-noto-mono
fonts-noto-unhinted
fonts-opendyslexic
foomatic-db-compressed-ppds
galculator
gdb
gdebi
gdisk
genisoimage
ghostscript
ghostscript-x
gksu
gnome-disk-utility
gnome-keyring
gnome-orca
gnome-session-canberra
gnome-system-tools
grub2-themes-ubuntu-mate
gstreamer1.0-alsa
gstreamer1.0-plugins-base
gstreamer1.0-plugins-good
gstreamer1.0-pulseaudio
gstreamer1.0-tools
gstreamer1.0-x
gucharmap
gufw
gvfs
gvfs-backends
gvfs-fuse
hddtemp
hexchat
hwdata
ideviceinstaller
ifuse
im-config
indicator-application-gtk2
indicator-sound-gtk2
inputattach
inxi
iproute
iputils-arping
iso-codes
iw
language-selector-gnome
libaacs0
libaccount-plugin-generic-oauth
libaccount-plugin-google
libavahi-compat-libdnssd1
libbdplus0
libbluray-bdj
libbluray-bin
libbluray1
libcanberra-gtk-module
libcanberra-gtk3-module
libcanberra-pulse
libdvdnav4
libdvdread4
libegl1-mesa-drivers
libfile-mimeinfo-perl
libgpod-common
libimobiledevice-utils
libmtp-runtime
libnet-dbus-perl
libnotify-bin
libp11-kit-gnome-keyring
libpam-gnome-keyring
libpaper-utils
libplist-utils
libproxy1-plugin-gsettings
libproxy1-plugin-networkmanager
libpurple-bin
libqt5libqgtk2
libreoffice-avmedia-backend-gstreamer
libreoffice-calc
libreoffice-gnome
libreoffice-impress
libreoffice-ogltrans
libreoffice-pdfimport
libreoffice-style-human
libreoffice-writer
librsvg2-common
libsasl2-modules
libtopmenu-client-gtk2-0
libtopmenu-client-gtk3-0
libtopmenu-server-gtk2-0
libtopmenu-server-gtk3-0
libtxc-dxtn-s2tc0
libwmf0.2-7-gtk
libx11-protocol-perl
lightdm
lightdm-gtk-greeter
lightdm-gtk-greeter-settings
marco
mate-accessibility-profiles
mate-applet-topmenu
mate-applets
mate-desktop-environment-core
mate-dock-applet
mate-gnome-main-menu-applet
mate-icon-theme
mate-icon-theme-faenza
mate-indicator-applet
mate-media
mate-menu
mate-menus
mate-netbook
mate-netspeed
mate-notification-daemon
mate-optimus
mate-polkit
mate-power-manager
mate-screensaver
mate-sensors-applet
mate-settings-daemon
mate-system-monitor
mate-terminal
mate-themes
mate-tweak
mate-user-guide
mate-utils
memtest86+
mobile-broadband-provider-info
modemmanager
mozo
network-manager
network-manager-gnome
network-manager-pptp-gnome
ntp
onboard
onboard-data
openprinting-ppds
pidgin
pidgin-libnotify
pidgin-otr
pinentry-gtk2
plank
pluma
plymouth-theme-ubuntu-mate-logo
plymouth-theme-ubuntu-mate-text
pm-utils
ppa-purge
printer-driver-gutenprint
printer-driver-hpcups
printer-driver-pnm2ppa
printer-driver-postscript-hp
pulseaudio-module-bluetooth
pulseaudio-module-x11
pulseaudio-utils
python3-aptdaemon
python3-aptdaemon.gtk3widgets
python3-aptdaemon.pkcompat
qt4-qtconfig
rfkill
rhythmbox
rhythmbox-plugin-cdrecorder
rhythmbox-plugins
rtkit
samba-common-bin
sane-utils
seahorse
sessioninstaller
shotwell
simple-scan
smbclient
software-properties-gtk
speech-dispatcher
synapse
syslinux-utils
system-config-printer-gnome
system-config-printer-udev
thunderbird
tilda
tlp
tlp-rdw
topmenu-gtk-common
topmenu-gtk2
topmenu-gtk3
toshset
transmission-gtk
ubuntu-drivers-common
ubuntu-mate-artwork
ubuntu-mate-core
ubuntu-mate-default-settings
ubuntu-mate-libreoffice-draw-icons
ubuntu-mate-lightdm-theme
ubuntu-mate-welcome
ubuntu-release-upgrader-gtk
ubuntu-sounds
unity-control-center-faces
unzip
update-manager
update-notifier
usb-creator-gtk
usb-modeswitch
usbmuxd
vbetool
vlc
vlc-plugin-notify
whoopsie
wireless-tools
wpasupplicant
x11-utils
x11-xserver-utils
xbitmaps
xbrlapi
xcursor-themes
xdg-user-dirs
xdg-user-dirs-gtk
xdg-utils
xkb-data
xorg
xserver-xorg
xserver-xorg-input-all
xserver-xorg-video-all
xterm
xul-ext-calendar-timezones
xul-ext-gdata-provider
xul-ext-lightning
xul-ext-ubufox
xzoom
yelp
zenity
zip