Mélusine: I can't speak for *all* tablets, but on iPads you can select text by putting your finger on the beginning (or end) and hold, and then drag to the other end. after letting go, a little menu appears, where 'Translate with Google' is an option (as is 'Lookup' which googles it, nice if there is a word or phrase you don't know). I have no other tablets, but I would guess Androids offer something similar.