Custom Newsletter Block w/ Name, Custom Field and Email

Hi, I would like to have a custom Newsletter Block. Currently I only have the option to have First Name, Last Name and E-mail, or only E-mail.
Is there a way I can change First Name to just Name and Last Name to Area of Interest for example.

And will this be reflected in the information stored by the block, or will that information still be stored as First Name, Last Name and Email?

Thanks in advance! 🙂