R’ Moshe Feinstein (Igros Moshe Y.D. 2:76) discusses scrubbing a plastic tablecloth on Shabbos. He says to avoid any issue of Melabein, one may scrub it gently but not vigorously. I am wondering whether this applies to my tablecloth that I use on Shabbos? It is not made out of cloth or a fabric, but it is not a traditional plastic tablecloth. I don’t know what material it is made from (there is no label in which the materials are listed) and so I am wondering how I can determine what its status would be in regards to melabein? Is there some test I can perform to determine this?
My apologies, but I don’t know of any test that you can do to determine the type of material that your tablecloth is. in th mean time you should be careful with it and act with it as if it a cloth tablecloth