Quote 1
ROBIN
Do but speak what thou'lt have me to do, and I'll do't. If thou'lt dance naked, put off they clothes, and I'll conjure thee about presently; or, if thou'lt go but to the tavern with me, I'll give thee white wine, red wine, claret wine, sack, muscadine, malmsery, and whippincrust—hold, belly, hold—and we'll not pay one penny for it.
DICK
O, brave! Prithee, let's to it presently, for I am as dry as a dog. (2.3.26-31)
The comedic conjuring among the peasants parodies the scenes between Faustus and Mephistopheles. Instead of using magic to gain power and wealth, Robin offers Dick a lot of booze for free. These scenes make us think about what Faustus is doing with his powers, and whether it's really so different from what the peasants do with them. Bet that never occurred to Faustus.
Quote 2
ROBIN
Dick, make me a circle, and stand close at my back, and stir not for thy life. Vintner, you shall have your cup anon. Say nothing, Dick. [Chants.] 'O' per se 'O'; Demogorgon, Belcher, and Mephistopheles!
[Enter Mephistopheles] (3.3.29-32)
Dick's use of magic to help him steal a cup from the local tavern-keeper occurs just after Faustus has stolen a valuable crown, but also some food and dishes, from the Pope. Once again, the scene reminds us that at the end of the day, the well-educated and ambitious Faustus's goals are pretty similar to those of some simple peasants. At the same time, the ease with which they conjure suggests that Faustus's abilities might not be so rare or special after all.
Quote 3
CARTER
Do you remember, sir, how you cozened me and eat up my load of –
[Faustus charms him dumb.]
DICK
Do you remember how you made me wear an ape's –
[Faustus charms him dumb.]
HORSE-COURSER
You whoreson conjuring scab, do you remember how you cozened me with a ho –
[Faustus charms him dumb.]
ROBIN
Ha'you forgotten me? You think to carry it away with your "hey-pass" and "re-pass." Do you remember the dog's fa –
[Faustus charms him dumb.] (4.6.109-115)
Honestly, Faustus is a big fat jerk. When the peasants accuse them of magical misdoing, does he defend himself? No, he just does more magical misdeeds and makes them unable to speak, so no one will know the wrong he's done. While the scene is meant to be funny (and don't get us wrong, it totally is), it also reflects rather poorly on Faustus's character.
Quote 4
ROBIN
I walk the horses? I scorn't, faith. I have other matters in hand. Let the horses walk themselves an they will. [Reads.] "A" per se "a"; "t," "h," "e" – "the"; "o" per se "o"; "Deny orgon gorgon." Keep further from me, O thou illiterate and unlearned ostler!
DICK
Snails, what hast thou got there? A book? Why, thou canst not tell ne'er a word on't.
ROBIN
That thou shalt see presently. [Draws a circle.] Keep out of the circle, I say, lest I send you into the hostry with a vengeance. (2.2.5-14)
Robin displays a surprising amount of literacy for a stable boy. Despite Dick's claim that Robin can't read, he manages to puzzle out the word "the" and, with "deny orgon gorgon," a version of the word "demogorgon" (no, we hadn't heard of that word before either). Robin's attempts to practice magic are humorous, parodying Faustus's more serious attempts. But their funniness also reminds us that maybe Faustus isn't as special as he thinks, and we'll see that later when Robin successfully calls Mephistopheles.