Unfortunately, you can’t delete them or move them to the end of the list — this is just how the client currently displays the recent activity feed. The messages themselves don’t affect syncing, they’re just for your information. If you’d like this behavior to change, you can suggest it on the GitHub issue tracker for the Desktop client.
Exclude Teamfolder from local sync:
You can do this via the Selective Sync feature. In the Windows client, open the settings → click Manage Account → select the account → Choose what to sync → uncheck the Teamfolder you don’t want to sync.
This way it will stay on the server but not take space locally.