In the relevant paragraph we're told that it is customary for "well-bred" officials in the civil service to say something agreeable to their subordinates when giving them work to do. They would say things like "Here's a nice interesting affair" as a way of making their subordinates's work a little less boring.
But in this particular department, which we don't know the name of, the normal customs of civility are dispensed with when it comes to the poor, put-upon Bashmachkin. He is a regular butt of everyone's jokes and is treated by his superiors as a glorified serf. Whenever giving him work to do, they shove bits of paper underneath his nose and expect him to get on with it. They make no effort whatsoever to be agreeable.
The relevant passage is important because it gives us an insight into how Bashmachkin is treated in this toxic environment where none of the basic rules of civility apply. The vivid description of this wage slave's office and the torments he endures provide a background against which the story will develop. In due course, Bashmachkin will pass away and come back to haunt those who tormented him, those who didn't adhere to the customary behavior of "well-bred" officials.