What section on the Notes tab, shows the history of the work documented on the record?

"Journal" fields (like Work notes list or Comments list) are components that feed into the Activity Stream, but "Activity Stream" is the holistic view of the history.

The Activity Stream, typically found on the Notes tab of a record form, provides a comprehensive, chronological feed of all significant activities on the record, including comments, work notes, and field changes. It is the primary place to review the history of documented work.

"Diary" is not a standard ServiceNow term for this functionality.

"Timeline" is a feature that might show history in a different visual format, but the primary, common view for work documented on a record on the Notes tab is the Activity Stream.

The "Audit Log" (sys_audit table) captures all database changes but is typically accessed by administrators, not directly shown on the Notes tab for end-users as the "history of work documented on the record."