@pdonk
In short, what is written there is my favourite achievement in J->E translation.
Musashi begins by using the Japanese idiom 毒を食らわば皿まで. Somewhat literally, the Japanese phrase is 'If you are to eat poisoned food, then you might as well lick the plate clean'. The 'licking' is implicit rather than explicit. On its own, this fairly simply translates to "in for a penny, in for a pound".
But, then, Musashi begins to coin variations for the purpose of word play, modifying and extending that same idiom: next, he says 皿を食らわば盆までも. The literal Japanese could be translated as "If you are to
eat the plate, then you might as well eat the tray on which the plate is served."
Musashi continues: 盆を食らわば人までも - "If you are to eat the tray, then you might as well eat the man who brought it to you."
Musashi is manipulating the idiom both to make reference to the fact that Baki appeared to him as a banquet and to indicate that, despite Baki no longer registering as a 'banquet', he still plans to kill him. I spent a very long time coming up with what I wrote on those pages. I think (hope) I got it just right.