You might also want to try clearing cache.
Clearing cache does not seem to do much. As an experiment, I cleared the cache using the Tools | Clear Private Data | Cache box is the only item checked and Task Manager showed memory went from 255 MB up to 260 MB after clearing.
It’s now at 262 MB after composing this message. In fact, if I stop typing and watch the memory usage, it climbs at a rate of 1 MB a minute.
Jack