If you are using your cutting table, doesn't it already have a mat on it? That is what I have been using under my quilts when I tie so I don't get the carpet and can make sure I've gotten all the way through. You may want to flip it to the other side first. I haven't seen any negative effects to my mat yet (but I've only done this to about 3 or 4 quilts). I do use the opposite side I cut on so I don't damage my good side just in case though.
If your mat isn't as large as your table, then I would think Formica would work well, but I've never tried it myself. I remember someone (Mary???) mentioned using a sheet of vinyl flooring under quilts for basting on the floor in the thread on basting methods. A small piece of that may work well on your table too.
Charlotte