Administrator. Scenario 12 of 13. Workload
One more thing
You already have a full week: month-end reports, two inductions to organise and the usual inbox. On Tuesday your manager says, "Could you also take on the conference bookings? It shouldn't take long."
You know it will take at least a day, and you do not have one.
The principle
You are allowed to have a limit. Do not say a flat yes or a flat no. Show what is on your plate and ask what should come first.