If you want an even more neutral term, you could use "server"... But it's more common in USA than in Great Britain. (fireman=firefighter, policeman=police office, salesman=salesperson etc. so it can fit any gender)

I agree with Tom. I know that both female and male actors are referred to as actors, and this seems to be an increasingly common change. So, I expect that both men and women can be waiters?

The feminine form for waiter is waitress, but nobody would consider it unusual if you referred to a waitress as a waiter.