Hi OP, I am a total fan of picnics...
In the past I have packed homemade chicken nuggets (key is the spice in the breading/flouring), fruit such as grapes, strawberries and blueberries and veggies with dip.
Here are a few more ideas -- hope they inspire you and good luck
cheese /crackers and some sort of meat such as salami or ham
antipasto skewer of melon, prosciutto, fontana cheese, and black olives (drizzle olive oil and add ground pepper for garnish)
mini ham and cheese quiches
ham and pineapple skewers