That would definetly open interesting possibilities! But I’m afraid there’s nothing like that at the moment.
I have not tested it, but I highly doubt that you can use the list of tables returned by Piet’s suggestion to iterate through all the rows of each table.
Also, for a given table, there’s no way to iterate through all the columns without specifying them, though some have already suggested it: New formulas for columns - Suggestion Box - Coda Maker Community