B4J Question How can I make a list with sets of data?

Found a way
I can add a list as an item in another list

Yep, that's one way... and a good one.
It all depends on what you are trying to accomplish.

You can also use "Type" and add them to a List..
You can also create a "Map" and add them to another Map or a List.

There is also JSON - which is great when you want to post data to and from a website (for example).

There are hundreds of posts here with examples of each.
Use the search engine and study your options (like I have and learned SO much).

"Cat Skinning" - there is more than one way in B4X...