From the back cover:
Looking for Adventure? New cultures? Strange new socities with unusual customs? Travel can be a broadening experience, as long as you go where things are different.
Here, in one book, is all the information that players and fererees need to discover the diversity in the 11,000 worlds of the Imperium. Starting with the basic UWP for a world, Grand Census leads you step-by-step to detailed cultural characteristics, including details of the social structures, government institutions, languages, and technology.
Whether you're a Traveller player or a referee, Grand Census tells what you want to know when you arrive at a new world.