[Zubersoft]

The only way to do that would be to use the Sync Library feature and set the Sync Type to "two-way". To do this, tap the three dots at the top right corner of the library screen on each device, tap Sync Library, then "Sync to another device". Make one device the server, the other the client, and on the server device, set the sync type to "two-way". Then you can click the button to create the server, and connect to it from the client device. This will compare the libraries, and push changes from each device to the other. As long as you don't have any conflicts in those two libraries, this should just add all of the songs from one tablet to the other. If you only want to push changes in one direction, you can change the merge behavior to something like "Always use data from server". Make sure you create a library backup file on each device under Settings->Backup and Restore->Backup Library before performing the library synchronization so that you can restore the original library states if you ever need to.

Mike