To record the video, I just stayed after class one day and put my iPhone on a music stand. Since I teach in a school of music, the staff lines on the blackboard made it that much easier to draw the framework. After that, I just started the camera and went to work. In any case, you can see that the main time limiting factor in filling in the table is how long it takes to draw the letters.
All this leaves us with a question. Is it worthwhile to memorize the table, when we can easily pull one up anytime we need one? Perhaps not. But it is a fun exercise, a chance to practice one's memory skills, and a reason to spend a nice little chunk of time with the elements and how they relate to each other. It can also help to reinforce the connection between symbols and names.
And heck, sometimes it's just fun to show off!