I use my dining room table and it's 45"x71" and hubby made it to fit the dining room, hence the odd size. I love it and can't imagine sewing on anything smaller. I have my cutting mats on it so everything is right there. It's sturdy too. I would think any kind of folding table would wobble. My sister has a banquet table with a hard plastic top and when I was using her machine the entire table wobbled and made it difficult to sew accurately. So I am grateful for my table.
Look for something sturdy or your sewing will not be accurate. And size is important too. I think a bigger table is better because once your quilt starts getting larger you need the table for support to avoid pulling. Good luck.