All EXCELLENT suggestions!
For maximum reduction of drawing file size along with the file dialog acessibility we used to have with wblock, try using the "EXPORT" command, and select "DWG" file type for your output. It creates a W-BLOCK style drawing output, with the ability to interactively select the target drive, directory, and filename! ("W"standing for "WRITE to disk" from the earliest days of DOS AutoCAD)
note: By hard selecting the entities you want to include in the target drawing, you strip out ALL unwanted LAYERS BLOCKS and DIMENSIONING STYLES, along with other LARGE spurious entities. Results in absolutely minimum file size.
Alternately, you can type "ALL" at the select objects prompt, get all entities in the drawing, and create a duplicate of the drawing with unwanted items (as listed above) eliminated.
If you select the drawing you're in as the target drawing, you replace your heavy drawing with the much lighter result; sort of a super-purge. Just remember to NOT save, as you exit the current drawing!!!
Good Luck!
C. Fee