What are some corruptions Swift satirizes in the King’s questions to Gulliver about those who make up the House of Peers?

Satire is a form of writing where an author uses humor and/or irony to critique a people group; it is often used to comment on political groups. 
In this dialogue, King Brobdingnag asks Gulliver a great number of questions about the workings of England's government. He starts by asking about methods of political education for the lords (government representatives), about how laws are made in England, and about taxes and greed among the leaders. Later, he also asks about the custom of gaming, referring to gambling: 

He observed, 'that among the diversions of our nobility and gentry, I had mentioned gaming: he desired to know at what age this entertainment was usually taken up, and when it was laid down; how much of their time it employed; whether it ever went so high as to affect their fortunes; whether mean, vicious people, by their dexterity in that art, might not arrive at great riches, and sometimes keep our very nobles in dependence, as well as habituate them to vile companions, wholly take them from the improvement of their minds, and force them, by the losses they received, to learn and practice that infamous dexterity upon others?'

In this section of the conversation, the king is extremely concerned with the prospect of leaders becoming consumed by, or even addicted to, gambling and growing lazy and corrupt in their methods of money making.
Finally, the king concludes with a culminating remark on the workings of England's government. He suggests, from Gulliver's stories, that the government was only:

a heap of conspiracies, rebellions, murders, massacres, revolutions, banishments, the very worst effects that avarice, faction, hypocrisy, perfidiousness, cruelty, rage, madness, hatred, envy, lust, malice, and ambition, could produce.

Through the king's probing questions and curious conversation topics, Swift reveals corruptions and injustices that he saw in English politics that were prompted by rage, greed, and envy. Without directly attacking government leaders, he points out important issues that needed to be addressed in his society.
https://etc.usf.edu/lit2go/177/gullivers-travels/3632/part-two-a-voyage-to-brobdingnag-chapter-6/

https://writingexplained.org/grammar-dictionary/satire