As a photography assistant, I have:
Driven the car.
Unloaded and set up gear.
Driven to Home Depot to buy decor.
Inventory/charge/empty/dump batteries and memory cards before and after shoots to make sure we never have a chance of running out of anything or losing data.
Book travel plans and rental gear.
Answered questions from clients, collected payments/deposits, fended off botherers
Ordered the food.
Dumped and organized the files.
Ensured backups are running.
Waved meat and cheese in front of subjects.
Etc.