'It's the kind of thing you would know.'

[shootingstar]

(Nora and Dan are talking in their Pub after the last guests have left; there has been a quiz night )
(Dan: )
'Have Blake and Sophie gone home?' . . .
'Yes,' she said, . . . 'They were pretty on top of things.'
'Cool.'
'The answers tonight were something else. One of the teams - the one Pete and Jolie were on - thought Maradona painted the Sistine ceiling.'
Nora nodded and stroked Volts Number Two (her cat). . .
'To be fair, it was a tricky one tonight. Might take them from another website next time. I mean, who actually knows the name of the highest mountain in the Kara-whatsit range?'
'Karakoram?' Nora asked. 'That would be K2.'
'Well, obviously you know,' he said a little too abruptly. A little to tipsily. 'It's the kind of thing you would know. Because while most people were into rock music you were into actual rocks and stuff.'
'Hey,' she said. 'I was literally in a band.'
. . .
(The Midnight Library by Matt Haig, episode The three Horseshoes)

What does "would" express in the sentence "It's the kind of thing you would know"?

 

[emsr2d2]

In this context, it means "That's just the kind of thing that I would expect you to know".

It could be written like this:
A: I mean, really, who actually knows the name of the highest mountain in the Kara-whatsit range?
B: In the Karakoram range? Well, that's K2.
A: Oh, you WOULD know that!

When it's meant like this, the stress falls very heavily on the word "would".