Bulk Log Hours
Find your volunteer project. In CiviCRM, go to Volunteers > Manage Volunteer Projects. If you can’t find your project follow the instructions here, to add one.
Under Manage Volunteer Project, find your project and click Log Hours
Bulk Record Hours
Well, minutes actually. Pick a contact from the drop down, or add a new individual. Add all the individuals. Pick a role. Add the minutes. Use the dropdown to choose a status, usually completed. Click in the top row to copy duration and status to all. And click save when you are done.