Update:
keeping with the rounded edges that has captivated leland...

I cut some brackets to hold down the multiple blocks. Traditionally I use threaded studs and various clamping fixtures, but there isn't much room for them on the table, so I came up with a single "strap" of 3/8" thick aluminum to hold them all down with a bolt on each side of each block. The traditional clamps are the black bars on the right of the picture.
And here are the finished (and thankfully marked) brackets.
The table will be laid out something like this:

Although...having cut them already at midnight I am now looking at it with fresh eyes this morning. I may have to drill a new hole for the second down from the top right. Its god awful close to the top right block. Plenty of room to move around though, so its not that big a deal.
There are random holes all over this plate, but they aren't a big deal. The aluminum came from the scrap yard so it was very inexpensive. For what I need it to do, its perfect. I just have to move things around to capitalize on all the real estate of that plate. It would serve no purpose to buy a new chunk of aluminum just to drill holes in it anyway.