@MrsTumblebee Really?? You think they are phoning around caterers getting quotes, hiring waiting staff, contacting suppliers, making sure there are enough tables and chairs and cutlery and getting them in, coordinating with the laundry to make sure they have clean tableclothes, instructing the cleaners to give the room an extra clean before the meal, coordinating with a supplier to choose and buy wine and any other drinks and organising delivery, instructing the staff how to lay the table, contacting florists to get floral displays made and delivered, organising valets and parking and ensuring paths outside are swept and free of mud, getting staff ready with umbrellas in case it is raining to shelter guests from the car to the venue, selecting guest list, sending invites, sending out invites to fill unfilled places, organising a table plan, designing a table plan for guests so they know where to sit or staff to take them to their seat, organising staff to take guests coats, etc and having a system set up so they know whose is whose coat, making sure the toilets are clean and towels and soap etc freshly stocked with a staff member to nip in there during the event to do a refresh, etc etc. including any speeches, any guests that need to be specially greeted - there is often an audience with a few special guests individually with a Senior Royal that gets counted as another engagement.
Don't make me laugh if you are honestly saying Charles, Camilla, Kate or Andrew do all of this. They have an enormous staff household who will oversee this.