I have a 100% cotton tablecloth that I use on a table with a microwave on it. Because of the chance of food spillage, I also put a 20-gauge plastic sheet on top.
When I press buttons on the microwave, the microwave is pushed back slightly and drags the plastic with it.
Can you think of some way to anchor the plastic and/or the microwave where it is?
It occurs to me as I write this that I could insert some kind of spacer between the microwave and the wall so that it can't move backwards...