From the tree menu in connections window when i double click on a table a new window will open that shows the tables columns, data, constraints and so on.
Now if i double click on a second table the first window will close and i can see the details of only the second table.
Is it possible to open two or more tables at the same time in Oracle SQL Developer?
Open the first table and the click on the red pin icon on the top menu. it is next to the Actions, refresh and edit icons. After that you open the second table, then both tables will remain open.
You can also use the keyboard shortcut for the pin button is CTRL+SHIFT+P