Well, I doubt very much that a lot of surgeons have true essential tremor--its just not that common, especially at an age where you'd still be practicing-- but if you're asking if a lot of surgeons take beta-blockers to steady their hand? I'd have to doubt it... I've certainly never heard any surgeons talk about it
I've worked with hundreds of different surgeons at 8 different hospitals in a wide range of specialities from neurosurgery to plastics and I've never heard it mentioned. Just anecdotal, but based upon a lot of experience.
I have heard it mentioned for people who have performance anxiety induced hand tremor. Never tried it though. I imagine a practicing surgeon wouldn't need it. I don't think many surgeons have the actual movement disorder ET. It can start at any age and is progressively disabling. Not very conducive to a long surgical career.