Add a row to table via js

It is possible to do do this in LiveCycle but not Acrobat..

You can add fields using JavaScript, yes, but you can't use it to "re-flow" the document, so you'll have to leave empty space on the page for the additional rows, in advance.

Instead of adding additional fields you can spawn whole pages, though. So when the user reaches the last line of the table they could use a button to generate a new page with an empty table. This would require setting up a Template object and a script to spawn it.