To transfer your library, the simplest way to handle this is to create a library backup file on your tablet, transfer that to your phone and then restore your library using it. To do this, open MobileSheetsPro on your tablet, tap the three dots at the top right and then tap Settings->Backup and Restore->Backup Library. This will generate a .msb file in the folder you select which can be on the device or in the cloud. If you selected a local folder, transfer the file from that folder to the phone. Open MobileSheetsPro on the phone, then go to Settings->Backup and Restore->Restore Library from Backup. After the restore completes, you will have access to your entire library on that device. Let me know if you have any questions about this.
Mike
Mike