Using Ctrl-Tab to switch between tabs in gnome-terminal

I think this is not possible in gnome-terminal due to GTK, see bugzilla.gnome.org.

However, it is possible with terminator which is very similar (sudo apt-get install terminator). Once installed I had to manually edit .config/terminator/config to get it working:

[keybindings]
  cycle_prev = <Ctrl>Page_Up
  next_tab = <Ctrl>Tab
  prev_tab = <Ctrl><Shift>Tab
  cycle_next = <Ctrl>Page_Down

The Preferences -> Shortcuts menu will allow you to set most combinations, but will not accept Tab as an accelerator, allegedly because it's reserved by GTK.

However, as posted here there is an easy copy/pastable workaround:

gsettings set org.gnome.Terminal.Legacy.Keybindings:/org/gnome/terminal/legacy/keybindings/ next-tab '<Primary>Tab'
gsettings set org.gnome.Terminal.Legacy.Keybindings:/org/gnome/terminal/legacy/keybindings/ prev-tab '<Primary><Shift>Tab'

Verified working just now in Gnome terminal version 3.32.2-2 on Fedora 30.