In the Stuart period masques were particularly popular. James I was quite fond of these as was his son and successor though not nearly to the same extent. These would involve lots of food and rink, but also performances, games and 'japes' (can't think of a better way to describe them - basically pissing about). These were all quite extravagant affairs, largely taking place at the palace in Whitehall.

Hunting was also an important part of the courts routine and served as a means to discuss import matters as well. Again, this was more James I than Charles I.

I'm not to sure about more official government ceremonies, other than coronations (which were obviously not that regular) but it's worth noting that Parliament was a very important aspect of the governance of England at the time, in particular the Stuart dynasty, where the friction between the crown and Parliament dominated much of James I and Charles I reigns.

Peter Akroyd's book Civil War has more detail on the Stuarts, their court and the process of government at the time.