use hydroton to fill the table up and cover it with reflective material which also has some insulating value so that light and heat cant penetrate.
two planting options for a good weight that i have found is to use 64 plants in a 4' x 4' table with 12 days veg time and lollypopped for 8" to 12" long colas,
the other would be to use 25 plants in each 4' x 4' space and veg them for 20 days and top each plant when you have enough branches to leave 6 to 8 branches on each plant before you flip to 12/12.