Actually, unless I've misunderstood, this sample form should do it. Right click the link in the reply header and select 'save as' to save locally. Right click the saved copy and select design to open in design mode, then preview to try.
I'm lazy, so it only has 3 read only rows.... I set up the default values for those in Tools / Defaults and then used position() <= 3 for making the field read only. I also had to change the default for the repeating table in the repeating table properties so any newly added rows would be blank.... take a look and let me know if you have questions....