Question about setting up audit for specific folder

I need to setup auditing on a specific folder hosted on a Windows Server 2012.

I first setup auditing policy using GPO (within security policy), then I configured the audit settings on the required folder.

What I don't understand, is once I configure the policy, the server security log rapidly fills in with many events recording access to objects such as C:\Windows\System32\UIAutomationCoreRes.dll, and so on. Shouldn't that happen only after I configure audit setting on the required folder ?

Thanks!