Periodic Table Table
Ed Pegg Jr writes "Theo Gray, a co-creator of Mathematica, was originally a chemist. Needing a conference table, he created a Periodic Table using a variety of woods." It seems Theo is missing some elements for the table, in case you have any spare europium (in a proper container, of course) lying about. This isn't Theo's first piece of furniture. It looks like he has left a few spots for new elements, and it is nicely modular, in the event an element is found not to exist.
..... whose half life is measured in seconds. The heavy artifical ones.