Nope, you're not gross at all. I've seen other models eat/snack on something while camming, and their viewers didn't crucify them for it.
I've had DoorDash food delivery come during a cam time, and when that happens I figure well, I could either A) do the thing where I'm still on cam, but you see me lean my upper body over to "do something" (but y'all fucking know I'm eating...especially when you see my mouth moving...come on...lol) while keeping my burger out of cam's view, or B) I could exit chat very briefly to eat - even though I have limited cam availability as it is - and hope those guys will actually return to my room when I come right back. Most of the time I'm gonna go for option A. Unless the model is opening her mouth wide and showing you the chewed-up food in her mouth (Gross...lol), or eating during a private show where that wasn't requested, I don't see what the big deal is...especially if we're talking about a time when the room is quiet af and guys are just sitting there not even tipping for anything.
I would never eat, say, crabs while camming though. Lol. Waaay too messy, and too much work (getting the meat out) to be trying to do it in between catering to requests and all.