Try this:

I'd be willing to bet that this app will fix your database bloat problem with one click.

From their web page:

BLOB Errors: Blobs are data appended to the end of a record. Due to bugs in the built-in contacts application, conduit problems and memory corruption issues, corrupt Blobs can appear in the PIM databases on newer PalmOne devices and these can not be removed by simply hotsynching from the desktop to the handheld. Pimlico has seen several cases of users with enormous contacts databases (some as large as 40-50Mb (!) that were 98% garbage from corrupt Blobs. Image below was from a Palm user's contacts database that was 1.8Mb in size. After DbFixIt cleaned it up, 1.57Mb of wasted space was recovered, and the database was then only some 230k in size.