You can buy a cheap, thin piece of vinyl and lay down on your table, pinning it underneath the edges with a push pin (or perhaps blue painters tape), and that will help things glide. I had the same problem, and ended up refinishing mine, as it really caught the fabrics and they didn't slide at all. The vinyl provides a slick surface, and doesn't cost much. That might be something to try - then you'll know if it's the table or if you just need more practice.
Hope this helps :)