Emulating an editable grid in Forms

Emulating an editable grid in Forms

Hi
I would like to show a row of fields similar to a spreadsheet that are editable and if possible hidden and shown depending on another field which says how many rows should be displayed.

So if the user enters 5 in the other field, 5 editable rows of roughly 5 cells each should appear.

I haven't seen any examples yet of this in my searches so far.
Any help appreciated.

Paraic