Seasonal plastic coated place mats, over time, have a tendency of curling around the edges. Take two place mats that match and put contact cement on both mats and let cement set up, then stick them together for a sturdy place mat that you would have normally tossed out. There is a trick to assembling them, put a piece of paper on the place mat and press an edge then slowly pull the paper out. Read instructions on the contact cement container.
By Syd