Under Requests > All Requests in the WordPress admin panel, you'll be able to use the checkboxes on the left hand side of the request list to select multiple requests.
Once you've done that, use the Bulk Actions dropdown to perform actions on all selected requests. The available actions are:
Move to Trash
Merge Requests - this allows you to merge multiple requests into a single request
Set Status to... - this allows you to change the status of all selected requests at once