User guide of CUBA studio

Is there any user guide of CUBA studio around where use of different options are explained e.g. what is the use of “custom” in defining columns in a table? I have scanned the developers manual but it doesn’t cover to that extend. Thanks for guiding me if I have missed any existing documents.

The only user guide on Studio is inside Help panel of Studio itself (Help > Show help panel). When you select a visual component in the WYSIWYG designer, the context help displays some information on the component along with the links to documentation.

Please look at the section of the documentation describing the Table component:
The addGeneratedColumn() method is explained there. This method allows you to define a custom representation of a column.