I can't think of a way to make a memo, but I use two ways to get to frequently accessed information. One is to write a macro that will whisper it to you in chat when you click on the macro button. You can make the button visible in your macro bar only, or available to both you and players if that's desirable. That's a one-click method, but takes up space in the chat. The other way is to make two handouts. One has the information you want to access, and the other is a quick-reference macro. If I have a handout labeled "Item Saving Throws" (which I do) and I want to be able to access it easily, I type [Item Saving Throws], with square brackets as you see, into the quick-reference handout, and save it. I can then archive the Item Saving Throws handout. When I want to see it, I open the quick-reference handout and click on the link that was created from the square brackets, and the archived handout opens. You can have multiple links on the quick-reference handout, to create a library of the information you want to get at with two clicks. Just keep that quick-reference one at the top of the journal tab.