(Submitting this feature request because I've had a couple of customers who needed this feature for reporting)
Currently, when using Activities (eg Calls, Meetings) in Reports, the activity records are not "clickable" and only show up as text. In order to access the activity record, the workaround is to key in the activity objectID into this link: https://app.hubspot.com/calls/[portalID]/review/[objectID]
It would be helpful if the activity records were clickable from the report, just like the default objects in HubSpot, eg Contacts, Companies, Deals, for increased convenience.