You can use net pots on a table no problems. The roots may have trouble coming out the bottom, but they will come out from the sides. The problem is the roots that grow out the sides will end up getting damaged from the sun if they have no protection. You can either drape a sheet over the table letting the plants stick out and thereby protecting those roots, or dump some hydroton on the table between the pots. These will float up with the water, and after it drains, will protect the roots by settling on top of them.

SN