Yes, you can click hover over the form (in the view in your screenshot) then you will see an Actions button appear. One of the Actions is “Rename” and you can give your “Non-HubSpot” Form and name you want.
Have fun
Mike
Here to learn more about HubSpot and share my HubSpot Knowledge. I’m the founder of Webalite a HubSpot Partner Agency based in Wellington, New Zealand and the founder of Portal-iQ the world’s first automated HubSpot Portal Audit that helps you work smarter with HubSpot.
It’s good to note too that non-HubSpot forms pull an identifier and name from the HTML of the third party form as it loads on the page.
This means that even if you rename a form, if the HTML of the form changes it will capture as a new form with a new name and not add submissions to your renamed form.