The “Other” category that you see while syncing your iPad, iPhone or iPod touch in iTunes contains data such as, system files, contacts information, settings, app data, album art, caches, etc.
Normally the “Other” section takes up less than 1 GB of space, but at times it grow much larger. This usually happens due to a corrupt file.
What to do if the “Other” section is taking up an excessive amount of storage?
To reclaim the storage space back on your iPad or iPhone you will need to restore the device in iTunes. You should sync it before you restore to create a backup. That way you can restore it from a current backup to ensure that all of the correct settings, contacts, apps, music, etc., are returned to the device.
After you have finished restoring the device from a backup, you should see that the “Other” category was reduce significantly.
If the large amount of data remains, that indicates there is corrupt data in your backup. If that is the case, you would need to “Set it Up As New” after restoring the device. You would then need to manually return the settings and content.