Not marble, nor the gilded monuments (1): This line is likely an allusion to the lavish tombs of English royalty; in particular, to the tomb of Henry VII in Westminster Abbey, which contains a large sarcophagus made of black marble with gilded effigies of King Henry and his queen, Elizabeth of York. unswept (4): note that the pronunciation here is /UN swept/. with sluttish time (4): i.e., by filthy time.
In Elizabethan England the word "sluttish" could describe either a sexually promiscuous woman or a grubby, unkempt woman. Here Shakespeare personifies Time as the latter. br...