Laertes comes to say his goodbyes to his sister, Ophelia, and his father, Polonius, before he heads off to France. He warns Ophelia that Hamlet's affections might just be a phase. Then it is Polonius's turn to offer advice to Laertes. And he does: a lot of advice. Polonius runs through a slew of maxims, warnings, and pieces of advice. All of these are cliches, so there is not much substance to what he is saying. It's as if he's talking to hear himself speak, to make it appear that he is full of wisdom. He is like the parent sending his child off to college, trying to squeeze in as many life lessons as he can at the last second:
Give every man thy ear, but few thy voice;
Take each man's censure, but reserve thy judgment;
Costly thy habit as thy purse can buy;
But not express'd in fancy; rich, not gaudy; (I.iii.72-75)
Polonius goes on and on for over twenty lines. Polonius also feels the need to offer Ophelia advice. He, like Laertes, is skeptical of Hamlet's motives. So, he gives her a bit of a lecture as well. Ironically, he tells her not to waste any time with Hamlet and yet, here he is with his long-winded lecture to her, essentially wasting her time.