You can also drop the selected text just to the right of the rightmost tab, left of the "scroll tabs right" arrow. When you're over the right spot, a down-poin

You can also drop the selected text just to the right of the rightmost tab, left of the "scroll tabs right" arrow. When you're over the right spot, a down-pointing arrow appears indicating that a new tab will be created there. This actually works between any two tabs too, but the drop area can be smaller.