I bought clamps (2 to a package) at a dollar store for about $2 a package. They work great.....if your table edge is not so deep and wide that you can't use them. But recently I've begun using masking tape and that works just as well, I think. Not the blue kind but the wider cream colored tape. It sticks well -- in fact, will stick multiple times -- and holds the fabric. I think I'm done using clamps.
But I hate this part of quiltmaking so much that I'd hire it done if I could! Seriously, I really dislike it. However, the last one I did I used a larger table and it makes all the difference, I've discovered. A long conference table or even a large rectangular dining table works so much better than an oval drop leaf!