I wrote an article called Getting Organized and Staying that Way that might help give you an idea of what they are looking for.
Another question they might ask is "How would you ensure your boss is organized"? Here is what I would say:
Some examples might be having regular meetings with your boss to go over their calendar, having a good bring-forward system, organizing your bossâ€™s desk in a way that is suitable to both of you or setting up an efficient filing system. Keeping yourself organized will help your boss to be organized.
Many of these things you will get good at through experience, but they want to know you have knowledge about being organized.
All the best,