(Credit on this goes to the VBB newbie Blue Star. Maybe some people have already thought of this, but even still, it is very much worth mentioning.)
Open your ships.tbl, and use find and replace to change every occurrence of two spaces to one space. Make several passes until no more occurrences are found (find and replace always moves on after replacing something, so an 8 space section gets reduced to 4 spaces the first time, 2 the second, and 1 on the last pass). In my case, a 375KB ships.tbl was reduced to 284KB.
That is a lot of room.
P.S. Wordpad would crash when I did this, so I copied the text into WordPerfect, did the changes there and then copied the revised text back into Wordpad.