I think there is glow tape as well.
I can't think of anything edible that also glows, but you could put LED christmas lights under a white table cloth to get the table to 'glow'.
You could also glue those glow necklaces to the underside of a clear plastic plate to make the plate glow while they eat, each kid could have a different color or something.
D-Day June 12th 2008, D-Day #2 Sept 28th
D-Day #3 Feb 15th & 16th 2010, D-Day #4 Nov 29th 2010