The basic items that you manipulate on this tab are “Groups”. Different “Groups” are represented by different rows inside the table. The easiest way to create a new group is to select with your mouse some individuals inside the main window of StarDust:
... and then you can mark these selected individual as belonging to the same group by clicking the button.
You can “rename” the group that you just created by double-clicking on the “row header”:
Let’s give the name “CentralCloud” to our new group: