What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
I get that you are asking about how to add blank columns and rows to your jotform but I'm not sure that I fully understand what it is that you are trying to do beyond that.
Are you just looking to create a sort of blank row and column within your jotform that is completely empty with no titles in it?
Or did you want something like a Matrix possibly?
Can you please explain a little more about the workflow you seek involving the columns and rows you want to generate for your form so we can better assist you.