"the misterious anxiety of them and us"
The author most likely included the following sentence at the end of paragraph 1 to
In a way there were too many of us for the food served, or it felt like that.
show that the caterers had badly underestimated the number of people that would be attending the feast and the size of their appetites
confide that the host was going to have to find a way to get more food at the last minute
reveal the fact that there was not enough food for all of the guests
introduce tension and demonstrate the narrator's subjectivity