Firstly, I agree with what Harry T said.
Secondly, I do not think Android has a better tablet gaming app library than iOS. I own an Android tablet, and though I didn't buy it for gaming, I was disappointed to see that many games I wanted to play were iOS exclusive. (And there were also some available for Android, but not for my specific tablet.) However, this does depend on what kinds of games you like. If I were buying a tablet for gaming, I would buy an iPad. (Unless I were emulating)