Mostly when I see this played, the Polonius says this as if Hamlet’s buzzing were an affront. He says this as if he were a sweet old lady from the South with her hand pressed over her housecoat over her heart saying, “Well my word!”
But in wondering what would follow this, what line Polonius might be about to say where this dash is, it occurs to me that what lines likely about to say is what he does, in fact, say next, that is, he’s swearing upon his honor that the actors are come hither are the best actors in the world. That is – what if Polonius doesn’t pause for Hamlet to say either of his lines here and Hamlet just talks over him?
The Hamlet Project 