Current rules for the official testing are that kids cannot sit at the same table. So, sure, I guess if your child is taking it alone, it could be in the cafeteria by himself/herself or an office or a computer lab. But it also requires an area where people are not coming and going, and the cafeteria is high on traffic. Maeve, the rules may have been different years ago when you were in high school (if you have a child taking it now, then you went to high school 15 - 20 years ago?), but it is a new world now. Lots of pressure and kids who have no objection to cheating.
If your concern is that your child will be in the cafeteria testing alone and you are worried about crumbs on the tables, I would suggest just bringing wipes. Studies have shown that gets rid of the food protein (referring to allergies, not microbes). You don`t need any special accomodations to bring in a couple of wipes, clean the area, and get rid of the wipes (hand to the proctor or put them in the trash). I did that for each test I took just to feel more comfortable. If you are worried about your child being exposed to food from another student, that won`t happen, because no food is allowed to be out. They are extremely strict about that.
I also took these tests at several different locations (four different schools for all of these tests, two of which I had never been to before), and the rules are the same everywhere. There can`t be a different standard for different schools. They take this very seriously (much more so than even final exams in high school).
I also did an SAT prep class, and they said everything I said above. No eating, no food can be out, you can bring a cell phone into the room, but have to hand it in to an area in the center, two students cannot be seated at the same table, so desks are used, etc. Same rules thoughout the U.S.