Pall Mall is where the Ferrars reside in London. Pall Mall is located near St. James's Court, where Parliament would convene. The proximity to nobility says a lot about their socioeconomic status. It signifies both their wealth and significance in society. Comparing this to where the Steeles reside, several miles North, emphasizes the incompatibality of Edward and Lucy when it comes to the expectations of Mrs. Ferrars. 

Austen, Jane, and Kathleen Viola James-Cavan. Sense and Sensibility. Broadview Press, 2001.