I'm a surgery resident. Don't LIE, we'll see right thru you anyway. You don't have to want to do surgery or even really like surgery.
We only ask that you put enough time, effort, and interest into your rotation to take something from it that may help you in your overall medical education. Surgery cares for the same diseases medcine does, just with surgical treatment instead. So if you plan to go into any medical specialty, there is a ton you can learn on surgery if you put the effort in. Some of our best students have honestly said they want to do IM or EM or peds or whatever, but still worked their tails off, asked lots of questions, and read up about what their patietns had, came to the OR prepared having read something about the procedure and why this particular patient needed it - these are the ones who will succeed on clinical evals, the ones who show they are interested in learning something from the rotation.
You do have to find out about your school's grading structure though. At most places I'm afraid it is the test which separates honors from the rest. I feel strongly that this is wrong, as you are on clinical rotations and should be graded on clinical performance, but this is the way it is at most schools. The tests continue during residency though (surgery residents at least take a yearly exam), so you might as well get used to reading a lot when you come home from a long tiring day of work.