This is the scene where Biff and Happy meet Willy for dinner after Biff went to talk to Oliver about investment
Why don't you let me finish?
We now see Willy getting very angry at Biff showing how they act as a family. People in public places do not raise their voices but Willy gets louder as he is trying to get his point across which shows that the Loman family has trouble communicating their feelings.
I'm not interested in stories about the past or any crap of that kind because the woods are burning , boys, you understand? There's a big blaze going on all around. I was fired today.
Biff and Happy are shocked to learn that their father was fired from his job.
How could you be?
The waiter, Stanley, brings them drinks and everyone stops talking.
Willy tries to change the subject because he does not want to talk about his failures to his children which means that as a family they do not use eachother for support. Biff is angry because Willy is changing the subject
Did you see Oliver?
This moment is a great representation on their family dynamic because Willy is making biff upset by changing the subject. During this happy is going along with it but Biff is still on the topic about Willy getting fired. They move at different paces emotionally which is where a lot of the heated discussions come into play.