How to enter a tab character in vim with SuperTab plugin enabled?
I've not used this extension myself, but I would guess that ^V-Tab might work. ^V in general can be used in insert mode to insert a literal keystroke instead of whatever that key is mapped to do. So you type Control-V, then hit whatever key or key combo you want to insert literally.
If you want to simulate pressing
<tab> as if SuperTab were not installed (i.e. you want to insert a tab that respects your
:set expandtab settings) then press Ctrl-Tab.
^V-<tab> inserts a literal tab. If you have
:set expandtab enabled then this might not be what you want, because it inserts a real Tab character, not a series of spaces.
You could also use the indent functionality by typing
>> which depending on your indent settings would use a tab character.