In which Jane Austen novel is there a mishap at dinner over seating arrangements? Why were seating arrangements important during that time period?

I know Jane Austen's novels well and yet find myself flummoxed over identifying "a mishap at dinner over seating arrangements." What comes to mind, however, is Lydia's arrival home in Pride and Prejudiceas the newly married Mrs. Wickham. Though the youngest of the five Bennet daughters, this 16-year-old is the only married woman among them. While immature, silly, giddy, and having recently almost destroyed the reputation of her entire family through her rash elopement,...

I know Jane Austen's novels well and yet find myself flummoxed over identifying "a mishap at dinner over seating arrangements." What comes to mind, however, is Lydia's arrival home in Pride and Prejudice as the newly married Mrs. Wickham. Though the youngest of the five Bennet daughters, this 16-year-old is the only married woman among them. While immature, silly, giddy, and having recently almost destroyed the reputation of her entire family through her rash elopement, her status as a married woman gives her precedence over her sisters, meaning she has the right to lead the rest of them into dinner. She triumphantly takes "Jane's place" as the highest ranking female in the household after Mrs. Bennet. Lydia makes much of this status and her new rights, and also insists that she will soon find husbands for all her sisters. Elizabeth's reaction is not at all happy, feeling her sister should have some sense of humility about how close she came to being a disgraced woman, almost loved and left behind as damaged goods by Wickham.

Seating arrangements were important at that time period because the society was highly hierarchical, meaning that everyone had a strictly defined place in the social system: aristocrats outranked commoners, dukes outranked earls, earls outranked barons, and barons outranked baronets, while married women of a particular social strata ranked higher than unmarried women of the same strata. It was believed important for the smooth running of society that everyone know their proper place and adhere to it. In Emma, for example, Emma would like to open the local ball, but accepts that she must give way to her hated rival Mrs. Elton, who outranks her because she is married to the local clergyman while Emma is single. 

Austen both satirizes these arbitrary social rankings by showing unworthy people like Lydia outranking worthier souls, but uniformly has her characters acquiesce to the social rankings as part of the order of being.