I run a package called "Aviation Tools Free" on my Android Phone, which could potentially be really useful on a larger tablet in the cockpit.
There are also various nav (and even INS) apps for Android, so much potential.
A pdf reader renders any tablet able to read approach plates, etc. downloaded free from various IAPs.
It would be very easy to run a PLOG on a tablet. I have done this on a Sony reader which worked okay, but at the end of the day I preferred paper for the purposes!
G