ham roll ups are easy to make a day or two ahead, not super messy to eat and you can fill them with almost anything.
Lay the ham slices flat, spread a thin layer of cream cheese (room temp) over ham slice then line one edge with filling choice (matchstick size pieces of gherkin pickle, green onions, or chopeed green olives) and roll up from the filling to opposite edge. Wrap in seran to chill then slice in little rolls to serve.