The writer chooses a mutton chop because it's the cheapest item on the menu. He's now reached the stage of his nightmare lunch date where he realizes that his companion is eating him out of pocket. So naturally he wants to spend as little money on himself as possible.

Remarkably, the lady reacts to his meager choice by lecturing him on the dangers of eating too much meat. According to her, chops are such heavy things, and she doesn't see how it's possible to do any work after eating heavy things. For good measure, she then goes on to say, in complete contradiction to all the available evidence, that she doesn't believe in overloading her stomach.

The lady is clearly not just greedy and hypocritical, but also completely lacking in basic self-awareness. She's eating this poor young writer out of pocket yet continues to insist that she hardly ever eats or drinks anything for lunch. She even has the audacity to lecture the writer about the heaviness of his humble mutton chop despite gorging herself on all the rich delicacies on the menu. She might well happily chat away on art, literature, and music, but her main focus is on having a slap-up meal at a swanky restaurant at someone else's expense.