The article I linked to has the information you are looking for. Or you can setup a slide show on a timer so don't need to touch anything, or sit on the side of the iPad and you can swipe across from the top if you want manual control, that will keep the image mostly clear from your hand. You can also use an iPhone to control the iPad https://support.apple.com/kb/PH24165?viewlocale=en_US&locale=no_NOIt is for just a few people at lunch or dinner table. Perhaps 4-6 people at my men's group dinner in a restaurant. I will setup the iPad at the end of the table and run it from the other end with my friends sitting closer than I will be. This will avoid fingerprints and having my hand in the way and having to sit close. I want my friends to be able to sit close.
I still haven't heard from any one that uses a mouse to "swipe" to the next photograph for example color photographs of my a travel to Cuba circa 2016 I am waiting to buy the largest iPad when I find out that it will work for sure. My last iPad "disappeared" from my car.