I did use picnic tables when I first started for indoor meals, but I much prefer the Ikea round table with matching chairs. The kids are separated when they have their own chair which solves the "he's touching me" problem you might get if they are bench seated. Also, I like that a chair has a back on it to support their backs and keep them from falling backward off the picnic table. I also find the table has more crafting room. I think the Ikea table and chairs was at the most $100.00.
If you do opt for the picnic tables, shouldn't they be going on sale soon as it is a summer item?