The Pending Signature Requests report is a list of tenants who have been sent a document to sign but have not signed it yet. It's the same information that would show if you filtered the Comms>Esign tab by Status=Pending.
The tenants with 0 Number of Attempts and a blank Method Sent and Last Delivery Date are tenants whose documents are still awaiting their signature but they have moved out. To clear those tenants from the list, go to Comms>Esign, search for the tenant, and click the Cancel button.
To clear any other tenants from the list, either follow up with them to obtain their signature or click the Cancel button on the Comms>Esign page. You can resend the documents to the tenant via the Comms>Esign page's Resend button.