Add additional rows to a PDF form if required

[tbrookes1980]

I am using Acrobat Pro to create a complex form for work. I want to create the form with a button that allows users to add more rows in response to questions if needed. e.g What are your current areas of research? Some users will only have 1 or 2 but others may have up to 10. I don't want to have lots of blank rows as the form is quite long to begin with. Is there a way to design the form so that only two rows appear to begin with but the user can add more rows if needed?

Thanks in advance