There are two times in the OT where we see how the Empire deals with garbage in space. The first is the trash compactor scene on the Death Star in ANH. The second is in ESB where Star Destroyer ejects a bunch of debris into space and the Falcon crew hides among it to escape.

So my question is: why does the the Empire generate so much scrap metal?

For the Death Star trash compactor, there might be some organic waste (the space squid has to eat something, and Han complains about a smell). But it mostly seems to be bits of scrap metal of various sizes, plus some lengthy pipes, dumped in a pool of stagnant water. I could almost buy that this is leftover from the Death Star's construction, but in ANH it seems to be basically fully operational.

Things get even weirder though when we look at the Star Destroyer scene. It would be one thing if it ejected a bunch of barrels full of waste, or some big compacted trash cubes like in the movie WALL-E. But no, the Star Destroyer ejects *over a dozen\* pieces of scrap metal/equipment, most of which seem to be around the same size as the Millennium Falcon if not bigger.

Where does this stuff come from? The obvious answer is that it's debris from ships/space stations, perhaps even from the Battle of Hoth. But why is the Empire carrying around such huge scraps if it's just going to dump them anyways? What we see has to take up a lot of hangar space.

I've never served on a real world military base or naval vessel, but I have to assume they don't generate nearly as much scrap metal.