teamwork files can have major issues with "bloat", and there is often not a lot to do about it, other than cut way back or create a new file.
Things I have seen trigger major issues of file bloat:
-latent users connections (that is, excessive numbers of users not working in the file, but with local data connections)
-high polygon count
-excessive use of solid element operations (and other trimming bodies)
-excessive linked and/or embedded external drawings (pdf/dwg)
-large embedded libraries (break out a project library if your e/l gets over 300mb)
-large items in the e/l (keep image files below 3mb and objects below 5-10mb)
-excessive 2d content in isolated views. This is a big one, and a surprising one. 150,000 2d elements (lines, fills, etc) on a worksheet will add more to your file size than 150,000 polygons IME.
-make sure (independent) sections and elevations get cleared out of the project map. these can stack up. but IME, don't add much to file size.
let me know if you want a second pair of eyes on it. I do audits specifically for file performance issues for a few firms.
BIM solutions and trouble shooting (self proclaimed) expert