I have a banquet table that I put a large piece of plywood on so tthe area measures 4x8". I use 505 .spray basting and binder clips. I do not center the backing on the table but rather lay the backing so one edge is on the edge of the table making sure that there is enough batting and backing for the top. I the spray the backing, place the batting on it and smooth,then place the quilt top on I then fold down 1/2 the top , spray baste and smooth out. After that part of the top is sandwiched I then move it over so the other side is on the table. When I do the spray basting I flip the layers over, spray and the position. I usualy have to spray baste the batting although I really prefer the spray the quilt top.
The reason that I do not center the quilt on the table is that by putting it on the edge I only have to move it once.