Back on Starbug, a very tense dinner is underway as Kryten has clearly gone off the deep end. Everyone is afraid to say anything to him, until Lister requests brown sauce to go with the lobster.
The scene depicts a tense dinner on the spaceship Starbug where Kryten's erratic behavior creates a sense of unease.  Lister's request for brown sauce provides a moment of relief and normalcy in the otherwise strained atmosphere.