The best way to move your database from Windows to your Mac is to back it up on Windows and restore it on the Mac, rather than exporting and re-importing your hands. See the
Backup and Restore guide for the steps.
The database growth you described is not a known issue and I haven't been able to reproduce the database size problem on macOS, so we'll need more information to look into it. Please send us a support bundle and a sample of the hands you exported:
1. Turn on 'Enable Logging' in PokerTracker 4 via 'Configure > Options' if it isn't already enabled, then restart PokerTracker 4.
2. Start importing your hands again and let it run for a few minutes.
3. Without restarting PokerTracker 4, click 'File > Create Support Bundle' and save the file.
4.
Zip/compress a sample of the exported hand history files you're importing.
5. Attach the support bundle and the zip/compressed file to a
Support Ticket.
Tutorial: Reporting A Problem