Tiffin is a British Indian term for a light morning or mid-day meal. However, says Wikipedia, “When used in place of the word “lunch”, it does not necessarily mean a light meal.” This 1950 menu for CP steamship service from Vancouver to Skagway appears to use the term in place of “lunch.”
In fact, this appears to be a regular table d’hôte lunch menu, unpriced as meals were included in the price of the ticket. In addition to appetizers, soup, and salad, diners could have their choice of entrées including a cold sideboard of various meats. A variety of desserts and beverages are also listed.