If you want to edit appointments via userform, it will take a bit more work. Userforms are really nice and handy in many situations. Their biggest downside lies in the fact that you have to program 100% of them. This is a downfall of VBA, honestly. Most modern tools are much, much more forgiving.

As far as your solution goes, we can leverage the form already created. What I would do is create another form with a listbox pointing to your Table. Then, if a user double-clicks on a list item, have it launch that first form and load it with that rows details. If the user changes it (i.e. clicking "OK") then update the Table accordingly, otherwise just unload the second form. This is actually a very good exercise if you've never worked with userforms before. I'll code that real quick. In the meantime, study the code and try to step through it so you can see how it works. (Hint: F8 steps through the code. Setting breakpionts (F9) helps as well.)