I bought one of these back when they had them on sale cheap with the idea of putting a drill press on it. I should have checked it out in the store first because it is way too short for me to put any kind of bench tool on. In my opinion it also lightly constructed and not capable of handling a...
They are used to attach the optional side boxes (7 drawer, short cabinet, tall cabinet). If you look at the bottom of the sides of the roller cabinet you'll find holes that they should thread into.
Rick
There is an entire Yahoo group dedicated to these saws, the identical saw is available from many vendors. With a couple fairly simple modifications they work fine. There's also some good information (and a warning) at: http://www.mini-lathe.com/Bandsaw/Bandsaw.htm