Yes, of course, it depends on the table. If there are a lot of crazy people at my table, I raise a little bit more, so I can be sure, if they call it, that they have at least something. If there are a lot of strong players at my table, I might even go All-In and try my luck against K-K. If I am the chip leader, I go All-In, because the others might think that I am trying to simply apply pressure, and I eat their stack, or I loose just a little portion of it. But A-T suited is a really strong hand, and you should play it confident. Even if you loose - poker is luck for at least 30%, and you can not win every torunament. So it's better to risk it for a chance of building your stack, vuz if you want to get to the final table, you need to do such decisions. If not with A-T suited, than with what?
Especially if you are up against only one player, and the other seven have folded, means most probably there ares still three Aces in the deck.