Indesign work files have huge file size
I am used to work with older versions of indesign, and sometimes quark. The file sizes I am used to is around 300 Mb at most. On the newer indesign I get file sizes up to almost 3 GB! All the images I use combined in the document is not even a quart of that size, and I do not embed any images. This takes up a lot of space and makes it hard to work in a network environment.
Well, that's the advancement of technology. On a 64 bit system, Indesign uses approx. 580 MB of RAM just after the start, with no document open.
Also simply doing a fresh "SAVE AS" and overwriting your file can cut down the size, sometimes significantly. The size tends to accumulate as you do regular SAVEs, but SAVE AS seems to write a fresh/optimized copy.
Steve Edwards commented
Have you tried saving the document as an IDML and then opening that then resaving as an INDD file. We have some files that have been worked on a lot over the years and they become bloated. Usually doing the IDML save gets rid of a lot of the stuff you don't need. It may not work but I'd give it a go.