I'm sending this from a Mac, but I don't use iTunes because I don't like it. That said, you can convert some files for non-Apple devices from within iTunes. Here is Apples support doc on doing that: iTunes: How to convert a song to a different file format
I said "some" because if the file uses DRM you're out of luck. "Fair Play" has been removed from music downloads, but if you bought before March 2009 the song would likely still have it. A lot of video content is still in a protected MPEG-4 (H.264) format. iTunes can't convert that stuff.
DoubleTwist seems to be the app of choice for syncing iTunes content to Android devices. Samsung Galaxy phones are supported, not sure if that also means tablets.