I'm creating a module to add a new delivery method to the store. I followed that tutorial (I will not transcribe it, it's great and is not necessary for the question).
The new method takes into account the buyer's country, product weight or volumetric weight.
The problem here is that in order to set the freight value according to the volumetric weight, it is necessary to create in the module management area a table where I can add a country and fill in its respective divisor (an integer value).
I know set fields through the file "system.xml", but I do not know how to create this PivotTable to receive N rows as the customer is adding new countries.