I’m not sure exactly which speech you’re going off of (because there’s two) so I’ll do both.
Lady Macbeth believes that her husband is a coward for not wanting to kill the king. She knows how badly that both of them want the power. Macbeth doesn’t want to kill the king because the prophecy will make him king either way however, Lady Macbeth wants to become queen faster.
Lady Macbeth explains how her husband is being delusional & this is normal. While he exclaims about how ghosts are currently at the table.