Here is a short video showing my two favorite ways to rename tracks inside Pro Tools.
The first way is to simply double-click on a track then hold down the ⌘ key and press either ← or → in order to navigate from one track to the next. Type in the new name and hop to the next track. Pressing ↩ will exit the dialog box.
The even faster way is to select the tracks you wish to rename then right-click one of them and select Rename from the pop-up menu. Type the new name then press ↩ to go straight to the next track. Pressing ↩ will cycle you to the next selected track until all tracks have been renamed, then it will exit you from the renaming dialog box.
Below is a short video showing these two tricks in action.
I type fast, sorry.