Need to add rows in an entry form

Need to add rows in an entry form

i want to create a form that askes for previous experience in jobs.
 
I want to capture about 3 column headers and have a row for each one, how can i create "rows" in the form builder.  All my questions have to come one after another in a vertical manor
 
any help will be great.
 
i have created a similar form in XLS but want to put it online in a form. any help?
 
Thanks