All your CRM activities like new contact, notes, emails, logs, and schedules will be displayed chronologically in this section. Hover on the tiny timer icon to the right of each task to see exactly when the entry was logged in.
To see the contact activity, navigate to the WP Admin Dashboard → WP ERP → CRM → Activities.
There are some useful filters on the top to help sort out things.
A shorter version of this Activity log is displayed in the Contacts section.