In the homepage, find the module and then the required action whose offline entry you wish to edit/delete.

Click on three-dot icon near action name. Then, select 'View offline records'. You are now directed to the screen with three tabs:

Local is a list of all entries that are stored on your phone and not synced with the server (this is where all offline data entries are stored)
Synced is a list of entries that have been uploaded to the server.
Failed is the list of entries that do not satisfy the conditions and cannot be uploaded to the worksheet.

How to edit/delete entries made in offline mode?