Depending on the type of iPod you are using, "Other" can be various things such as Album Artwork, Notes, Contacts, Firmware etc. or files that are on there if you are using the iPod as a removable storage device.
If you feel that Other is being incorrectly reported then try restoring your iPod. Restoring will erase the iPod's hard drive, reload the software and put it back to default settings:
Restoring iPod to factory settings with iTunes