Apple Contacts program freezes with Spinning Beach Ball

I rarely see the Spinning Beach Ball, except when using Apple Contacts it freezes all the time whenever doing anything with it. There are 11,000 Cards from when I started using it many years ago.

Any ideas why? I disabled a GMail, a non-primary Apple and a carddav.linkedin.com Contacts accounts.

Now there are one primary Apple iCloud account and a "On My Mac" account for 10,400 Cards. Switching off the primary iCloud account and leaving on just the "On My Mac" account there are 5,000 Cards. I don't know how to disable the "On My Mac" account. I assume I need the promary iCloud account for other connected devices. What should I do to make Contacts run quicker stopping the Spinning Beach Ball?

Thank You,

BC

[Image Edited by Moderator to Remove Serial Number]