When clicking on a Table in Oracle SQL Developer, the IDE will open the Table, but by default it will only open one at a time. Thus, it is not possible by default to open multiple View panes for viewing multiple tables at the same time. The IDE will expect the user to use the “pin” to pin a view and than open a new (second) view pane.
To change this behaviour change:
This will open all view panes with a “pinned view” and by default open multiple views of Tables: