Many cross stitch or other counted pattern can be used for filet crochet.

See section : Monochrome patterns

The size of the finished project depends a lot on the crochet hook, the thread you will use, and your own crochet/tension style. My best advice is to try out a 10 x 10 square piece and measure it, then times it by the size of the chart. This will give you an estimate of the finished size, and do remember that a filet crochet block is more rectangular than square.

A little word of advice. When making a large item, like for example a table cloth, make sure you buy a brand of yarn that is easily available. I have sadly learned that lesson the hard way by one time starting on a large table runner, with cotton yarn bought from a bargain bin. Sure enough I needed more and the shop was completely out ! It was a leftover sale, and would not be available again, that project was never finished.......