Its a traditional victorian 'high tea' with your choice of teas and pastries / cheeses on an ala carte basis. We consider this a must do on every trip.
Its also expensive that said , its a wonderful relaxed experience but not one for the inpatient or one with small children.
Now there IS a tea party for children held there and if you have kids thats what i would choose as menu and tea selections are kid friendly its had several name changes through the years and its now called the 'Perfectly Princess Tea Party'