How to change the tab name

I believe you want to update the browser tab name to reflect the same as your form title. Is that correct?

If yes, you will need to update the Page title option from your Form's settings page as explained here: https://www.jotform.com/help/373-How-to-Change-the-Page-Title-of-the-Form 

Please review and let us know if you are referring to something else.