The life of a medieval ruler would depend on the country, century and the ruler itself. In general though if one could say what a medieval King could do, there were options of hunting, jousting, banquets, attending mass, going on royal progresses, holding audiences and dealing with the issues of running a government.

A specific example I will give is Henry II of England who was a ruler in the 12th century. He was the son of Empress Matilda and Geoffrey Plantagenet, the Count of Anjou. He came to the throne based on his mother's claim and is the founder of the Plantagenet Dynasty. He was an excellent administrative King who was quick and able to move throughout the lands of his Angevin Empire. He was very hands on traveling in order to deal with the problems of running a government and hunting. "Addicted to chase beyond measure,; at crack of dawn he was often on horseback, traversing wastelands, penetrating forests and climbing the mountain-tops, and so he passed restless days. At evening on his return home he was rarely seen to sit down, either before or after supper." This was a description of Henry remarked by Gerald of Wales.

Sources: The Plantagenets: The Warrior Kings and Queens Who Made England by Dan Jones