Take a look here for information about the general mechanics of importing Excel data into a PDF form - you will need to use a tab separated text file, not a CSV file for this to work:
If you want to modify this code so that it only advances when you press a button, I would call the Doc.importTextData() method from that button, after the button increments the record counter.
Ok... I've been playing around with this and I am totally lost. I get this error.
NotAllowedError: Security settings prevent access to this property or method.
Doc.importTextData:8:Field Import:Mouse Up
I can import 1 record at a time, but not a batch import them.
If you're interested in a tool that will do it for you with a single click (pretty much), without having to mess around with code, check out this one I've developed and which you can purchase from here: Custom-made Adobe Scripts: Acrobat -- Mail Merge and Email
I probably should have mentioned that in my original answer, but because this is in the documentation - and you cannot program with any API without being familiar with the documentation - I did not even think of mentioning it.