During the British colonialism, British people thought of themselves as superior to people who are non-British. Since the British Empire ruled over other countries, British people thought that they are the original ones, and others are inferior to them since they are not British, and having the passport does not make them British. Just like the case with Mr. Kelada, he had a British passport but the narrator kept looking down at him because he knew that he comes from The Middle East. He also hated before he even me him, because his name was not British, because at that time, British people preferred to stick together and not to have foreigners among them.
The narrator is obviously British as he says he would prefer a cabin companion with a name like Smith or Brown. Typical characteristics of British gentlemen at that time were that they dressed in quiet colors, they did not talk very much and did not use gestures when they did. That is why the narrator uses so many words and expressions to describe how much and how Mr. Kelada speaks, to show that he did not behave 'properly'. Such as: chatty, exuberant, hearty, jovial...
Now Let's Play! : This game is a Crossword Puzzle, made to practice vocabulary:
www.educaplay.com/learning-resources/15552003-mr_know_all.html