>>I create a DE class and when I reference from my form with DEClass and DEClassLibrary properties, I can't add any table to the DE of the form. Is like it's in read only mode. Why?
>
>By design because custom DE class doesn't belong to the form.

Then I can not see how this simplifies abstracting the DE. What this effectively means to me is that you have to create a DE subclass for every combination of DEs you need for your forms. A DE with a Customer CA for my Customer form, a DE with an Inventory CA for my Inventory form, etc. A much easier implementation is for me to have a DE subclass for my usual DE code in the various methods without having to decide what cursors, tables or CAs go in the DE.