I found a 24 LED clip-on light at Lowes - Styleselections #0352725, $20.00. It is a brushed stainless gooseneck lamp with a heavy spring clamp. The clamp is connected to the goosneck with a hex nut. The clamp has padded jaws, so it looked like a good fit to connect to the EX-21 table.
The clamp is pretty strong, but anything on the table is liable to get in the way. So I measured the thread end of the gooseneck where the clamp attaches, and then the mounting hole for the hold-down on the EX-21 (which I removed when I got the saw). That was a good fit.
The lamp has an in-line switch - too big to fit through the hole in the hold-down bracket. I pried the switch open, but found it was a single pole switch - so only one wire was broken and the other fed straight through the switch and would have to be cut. I decided to cut the wire between the switch and lamp and add two crimp-on bullet connectors (1st picture). Stagger the bullets so you make sure to connect the + to + when reconnecting the wire, and put the female of the bullet on the power source side - that way if they come apart, the source side is insulated.
The other pictures show the lamp in place. The clip-on clamp is on the table just to show its size. The lamp is very bright and the gooseneck stays in place with the saw in operation.