Good point Quocunque. i felt there was something wrong with that clue, and you have just pinpointed it. It's the second word PLUS board, with board actually meaning a table to eat from. (I think it's late enough in the day now to post this link)
https://english.stackexchange.com/questions/29987/what-is-the-etymology-of-board-as-found-in-room-and-board
And going back to 4d, as well as agreeing with Chrise's point about the different number of middle letters per word being unfair, I am also in some doubt as to the definition being correct. According to all the dictionary definitions of the answer, it means to make someone else mad, not to 'get' mad. It's in the wrong tense to mean 'get mad'. So all in all, I think that was a poor clue.