After the end of Act IV there has been a pause, a silence of two days, like the waiting time while Jesus lay in the sepulchre.
Line 44 An alligator stuff'd . . .
in the Wunderkammer of this alleged Medieval apothecary, a specimen from America is also exhibited
Line 56 Being holiday . . .
in that season they could be celebrating either Saint John the Baptist or Saint James or Saint Mary Magdalene; all of them much revered "at that time" (be it the Middle Ages or the Renaissance)
Line 57 . . . Who calls so loud?
the Apothecary reacts like a conjured spirit
Lines 80-1 There is thy gold . . .
Doing some murder in this loathsome world
with a general meaning, but also a hint at the conquest of the New World; see Adam's vision of the future in Milton's Paradise Lost
Line 10 Where the infectious pestilence did reign
it had not been mentioned until now, however
"It is not clear why Paris is so anxious not to be seen" (Collins Classics edition). Maybe they feared some 'shame' on Juliet's part; for example, that she had committed suicide after having sinned with another man? But they would not dare say it (see line 51).
Lines 45-8 Thou detestable maw, thou womb of death,
Gorg'd with the dearest morsel of the earth,
Thus I enforce thy rotten jaws to open,
Broken open the tomb
one more reference to Jesus Christ -- and partly, a sad parody: see line 49