The only thing I can think of is to apply the liquid rubber non-slip stuff on the table edge and let dry. If the tables are super valuable then try the stuff on a leather scrap on the back and see if it would give the cloth some grab. I would try it on a scrap in case it discolours the leather. The other option is to get plexi glass cut to the table top size and put it over the leather cloths. It would keep the cloth in place and the plexi glass would be easy to keep clean. Maybe someone else will come up with some better ideas. Good luck!