What does Shylock mean in his Act 3, Scene 1 speech ("To bait fish withal... will better the instruction.")?

"To bait fish withal: if it will feed nothing else, 
it will feed my revenge. He hath disgraced me, and 
hindered me half a million; laughed at my losses, 
mocked at my gains, scorned my nation, thwarted my 
bargains, cooled my friends, heated mine 
enemies; and what's his reason? I am a Jew. Hath 
not a Jew eyes? hath not a Jew hands, organs, 
dimensions, senses, affections, passions? fed with 
the same food, hurt with the same weapons, subject 
to the same diseases, healed by the same means, 
warmed and cooled by the same winter and summer, as 
a Christian is? If you prick us, do we not bleed? 
if you tickle us, do we not laugh? if you poison 
us, do we not die? and if you wrong us, shall we not 
revenge? If we are like you in the rest, we will 
resemble you in that. If a Jew wrong a Christian, 
what is his humility? Revenge. If a Christian 
wrong a Jew, what should his sufferance be by 
Christian example? Why, revenge. The villany you 
teach me, I will execute, and it shall go hard but I 
will better the instruction."

Shylock speaks tersely in prose, not verse. He says he really doesn’t care if he has a “use” for Antonio’s flesh (he’ll use it for “bait” if nothing else)—“use” is not the point, as certainly Salarino should understand. Shylock also plays on the word “use” in the sense that as a money lender, he is a usurer, and so in not having use for Antonio’s pound of flesh, taking it becomes pleasure, not business. The pleasure is revenge, which he repeats four times: taking a pound of Antonio’s flesh enables him to get back at Antonio and all Christians for the way they have treated him. Shylock provides a list of his grievances in the form of very strong verbs, all in parallel order: Antonio has “disgraced,” “laughed at,” “mocked,” “scorned,” “thwarted,” “cooled,” and “heated” Shylock “for [he is]a Jew.” He follows this with series of ten rhetorical questions to argue that he, a Jew, is also a human being, having the physical features of a human (eyes, hands organs, dimensions, subject to diseases) as well as the emotional aspects of a human (senses, affections, passions). He then turns to the subject at hand, why he wants Antonio’s pound of flesh: “If you wrong us, shall we not revenge? If we are like you in the rest, we will resemble you in that.” It is human to seek revenge, he suggests; Christians do it and so does he, a Jew.