This vintage pattern is made available by Free Vintage Crochet.
This pattern provides instructions on how to make a placemat, a centerpiece and a coaster for your dinner table. It’s not very protective, but you can lay it onto another tablecloth. Or, line the backs of the individual mats for the protection that you need.
You will need a size 30 crochet thread and a size 13 crochet hook.