Nice quilt.
I use an 8 foot folding table, put risers under each leg. Mark the the center line down the table with masking table. Scotch tape about 4 round tooth picks down the center line [thus I can feel the center line through the sandwiched quilt], stretch out each layer clamp it down and just pin this center section of the quilt. Then move it over and finish one side at a time. This works very well and faster than the floor.