I have to agree that this table is probably not the official table made for the model 221 by Singer, and it may have even been made before the featherweight sewing machine was conceived, but it could have value to a collector. I wouldn't take it apart, at least not yet.
ewecansew is right that Singer never put the name 'featherweight' on their machines, but I'm not sure when they started calling the machine that. I looked at my FW card table, and there is nothing on the bottom except the serial number (stamped in) as far as identification. I don't think Singer let anyone else put advertizing on their products, and I *think* they made everything themselves. E.T. Burrowes was a company dating back to at least 1903 or thereabouts, and they did make things like this.
There is a gentleman on VintageSingers yahoo group who has researched the model 221 tables and put together several documents about them, available to group members. If you already belong to that group, you could contact him; if not, you could join; or if you don't want to join pm me and I will contact him for you. He might have information about this particular table if it was indeed made for a Singer featherweight.