HOW TO get data source registered in calc

In LibreCalc when you try to insert a Pivot Table you get a Select Source pop-up that gives you three options:

  1. Name range
  2. Current selection
  3. Data source registered in Calc

What is the third option? I couldn’t find much info and how do you go about registering data.

I would like to create a Pivot Table in a similar way to Excel where you can insert a table range and then use it in the same workbook or even in another one.