most tablets has low res, so the res of the video doesn't matter that much, the problem is the bitrate, which is one hell of a thing to render. you've seen a single 2hrs movie with a size of 30gb right?
this is evident with some copies that exist in BBT, i`ve seen 720p being bigger than the 1080p, just because the 720p has waaay higher of a bitrate than the 1080p. so in short, you watch out on the file size of the video, the res doesn't matter much i.e. if you play a 1080p movie on a 720p screen, the movie will automatically adjust and play @ 720p too, something like downscaling itself BUT the bitrate is the same.
but heres a tip, dont just grab a tablet and slap in some anime like a tard, first thing to do is to know what core components the tablet has, i.e. the processor and the gpu and the native resolution of the tablet's screen, once you know those, start googling and find some reviews about their performance and if they could drive a video on that native resolution.
like the old classmate i have, he saw a brandnew notebook for like less than 250$, and bought it like a tard, first thing he said was "wtf, notebook lags when playing 720p anime" because the notebook has a n270 atom +gma 950 with a native res of 1360x768...
