When you press F4 on a table, the describe window defaults to the column list which is fine but only the top half of the screen is filled, the bottom half is blank and (although it looks like it should be) isn’t resizable. If you then click on the data tab (or any of the tabs I think), the view changes and the full window is utilised. When you then click back on to the columns tab, it too is now using the full window.
I’m using 12.10.0.14 with the describe options: Stay-On-Top / All Describes in single tabbed window
Thanks,
Mark.