Something that's prandial relates to a meal. If you tell a prandial joke at the dinner table, it happens while everyone's eating.
You can describe things that happen while you're dining as prandial, and you can also talk about things related to eating as prandial. A prandial adventure might include traveling to Asia and eating local delicacies, and a prandial dispute might be an argument about what to serve for Christmas dinner. Prandial comes from a Latin root, prandium, "late breakfast or luncheon."