I currently have [...] BG3 Morrowind.
That would be a new game to me. Morrowind is an Elder Scrolls game, unrelated to the BG series.
If you want to add mods, the easiest way is to use the BWS (BiG World Setup) program:
http://www.shsforums.net/topic/56670-big-world-setup-an-attempt-to-update-the-program/I also wanted to get info on the tablet version of BG. Can you move from tablet to PC and back?
You can get the tablet versions of the Enhanced Edition games from the relevant app stores I believe (Google or Apple, depending on whether you have an Android or iTablet). And yes, AFAIK you should be able to transfer saved games from one type of device to another.