Although our store plans use stripped down fitting models (most a few hundred KB) sometimes you need more detail for presentation. Then it’s often faster, easier, to use raw supplier source files (usually supplied as ACIS Solids no matter what they use to make them) and accept the extra overhead.
Today I wondered why two outwardly similar pallet rack files differed in size by nearly 20MB. Opening the large one I found more than three hundred clothes hangers had been used to demonstrate the garment capacity. Those hangers were all individual, and reasonably complex, solids. That was probably a result of the export process but imposed a huge overhead.
Taking one hanger, creating a block, deleting all the ”loose” hangers, then inserting the same number of block instances made a dramatic difference. The result was a 3MB file instead of the original 23MB. It was quicker to open and much more responsive to work in.
Blocks aren’t new, they do take a bit of time to create but will reward that investment every time you touch the file. If there is more than one of anything, seriously consider making a block of it.