you can pick up fabric glue at any fabric store or at walmart or craft store, turn under the hem towards the underside, glue it, leave about a two inch opening,,, attach elastic to a large saftey pin, then run elastic threw it , pushing the pin along,,,,make sure to watch or pin the other end to it, so it doesnt go in, when you get it run all the way threw, take the two ends and pull till you get it as tight as you want, leave a little extra for adjustment,,,, tie them off or sew the two ends together,, you also can use a hot-glue gun, or even any type strong glue, (not elmers)
also, you can purchase fitted tablecloths in most large store today, walmart /kmart etc,,, if you just want one , not especially want to make it
i do think anything you give that you made is more special,,,,,