Ok, driving my ears crazy trying to hear the differences. Used audacity to convert wav to mp3 not sure I'm hearing much difference doing it in audacity.
wav file still is by far the best but takes up lot's of space on the tablet. I'll be having 40-60 songs on there.

Selected constant bit rate but it drops the quality from 320 to 192 no other choice available.
I'll check and see how wma files work later