Only info I could find:
The crates were presumably mostly found items and not constructed for the film. The cubes with the grooved sides and round holes on each face, for example, were made of vacuformed plastic, but nobody knows what for. A British company called RS Prop Masters, which makes stormtrooper costumes, says they found one but don't know what they were made for either. Two of these cubes were put together and painted blue to create the carrying case used by the Death Star scanning crew in Docking Bay 327.
Oddly, for a working bay used to capture and detain potential miscreants, the set is filled with an assortment of barrels and crates, many of which are out in the open where ships will land. This was probably in part to make the set look busier and real, but also because a cluster of narrow barrels was used to conceal the metal rod used to prop up the Falcon set.
The majority of the crates and barrels were probably regular commercial products in common use at the time. Many seem to be large plastic barrels for shipping industrial products or agricultural supplies or whatever, but painted to make them a bit more interesting.
From: https://sites.google.com/site/millenniumfalconnotes/part-iic-the-docking-bays