I love this idea. Tulle over linens. The look is so romantic. I believe the best part about this is tulle is extremely inexpensive usually running around $1 a yard you could do around 15 tables for probably $300.
This would work perfectly if you didn't want to spend extra money on custom linens but wanted a little more of a custom look. Tulle can be difficult to work with as its very flimsy and hard to cut but the end result is so beautiful it would be worth it.
p.s. Does anyone else notice the tent liner? How much more beautiful does this look without steel beams ruining the pictures! Always a great investment if your using a tent for your wedding.