If im reading this correct u want to be able to read tab and play it on a keyboard right???
Tab is read like this (as you already know)
E - - - 1
B - 2 - -
G - - - -
D - - - -
A - - - -
E - - - -
Basically then you would want to translate it to to notes.
for the first note you would add 2 ( as noted by the number 2 ) semitones to B so it would become C#. Then you would add 1 semitone to E for the next note which becomes F.
then on the keyboard you will play C# and F.
Do you understand semitones ?? Well i hope you were able to understand my post.