I believe the last section for opportunity attacks is for all Reactions - as they are a distinct action separate from Actions and Bonus Actions.
My suggestions for the UI would actually about separating out things like "at-will", "per short rest", and "per long rest / spell slots". It feels strange that for a spellcaster who uses cantrips as their primary attack - such weight is given to their weapon skills and their cantrips are mixed up with their spell-slot spells in the UI.
