I have to admit, this one has me stumped. It’s a 6″ diameter wooden ball that looks to be very well made. The “why” part is a mystery. Surely, it must have been made to do something, or go with something. I just have no idea.
The Trylon reference is to the Trylon & Perisphere that most collectors are no doubt familiar with. Even if you are not a collector, it’s always nice to know what those things are called, just in case you find yourself on Jeopardy one day, and the answer is “iconic 1939 New York World’s Fair symbols that everyone has seen, but no one knows the actual names of.”