Sampling and demonstrating is its own kind of stand work. You are handing something to a stranger, in a busy space, and the kit has to keep up.
The articles collected here cover that ground. There is a look at a stainless steel portable bar built for events in Sydney, a piece on mobile kitchens for sale, a rundown of what product sampling actually involves, and an older article on the factors that make the difference in food sampling and tasting.
Have a read before you brief a stand, and the practical side of the day is easier to picture.