tab button on main page in terminal layout

Tab button is placed on the page with other special keys like Fn, Esc and so on. Missing tab button on the main page is huge usability problem for terminal layout, because most shells support tab completion. Tab completion saves a lot of time and movements and it'd be very handy to have on a main page especially when working on small phone screen.

What about placing tab key on the main page? There is some space there.