When you drag a tab, an outline of the tab borders shows what will happen when you drop it: place it in above, below or next to another tab, or simply move it to another location among its siblings.

The tab header right-click menu also has a couple of choices for arranging all tabs at the same level as either "tiled" (the content of all tabs visible side-by-side) or "collapsed" (only the content of the active tab visible).

You can save your rearranged layout of an Object View tab so that it is applied for all objects of the the same type for the same database type. In the sub tab header right-click menu, just select Save as Default Layout. To restore the default layout, use Reset to Factory Layout.