From the 1970's, this is a 70s Vintage Tupperware oval steaming dish (1273-5) with lid (1275-3) and steamer insert (1274-4). It comes with a divider, or divider could be easily removed for one larger bowl.
Great for Rice or steaming vegetables...or just as a server.

One side is a little melted from dish washer but does not affect the steamer.