I was looking at something completely unrelated when I happened to open up the Activity Monitor and imagine my surprise at seeing Calendar at the top of the list using 5.61 GB of memory. I do have 3-400 things scheduled in the calendar, but nothing too complex (just time, date, repeat from here to here, no alerts or attachments anywhere) and even now about 30 minutes later it is still using that exact 5.61 GB of memory. Never seen anything like this before. Now, I know that I can probably fix this by restarting or even quitting the app, but this is an odd enough occurrence that I'd like to try digging deeper, partially for curiosity and partially for the possibility of submitting a coherent bug report to Apple. It doesn't seem to slow down the system so I am not in a hurry to fix it. I'd really like to see vaguely what is being allocated in this memory if possible (Open Files and Ports doesn't give any hints, at least not to me). Any ideas or clues to narrow this down?