In most cases, child tables are used as options for the parent, for example, take a products Database
you may have a products table and a categories table where the product can be assigned to the categories.
In the wizard, set the categories column to use a meny form elements type, then click the lightning bolt next to the menu to edit it;s properties, and set it to use the categories table, with the category ID as the value and category name as the label.
If you have a more complex table structure, you may need to build on the pages after the wizard has been created, for example adding the Manage Relational Table behavior to the insert and update behaviors if you have a linking table.
