Tiffin is a British English slang term for a second breakfast or lunch sometimes applied to any light meal.
It originated in British India over a century ago when the many Indians working for British companies disliked the British food served at work.
Tiffin service was created to bring home cooking to the workplace.
The distinctive tiered stainless steel, enamel or plastic containers are themselves called Tiffin widely used and easy to buy in Thailand.