Yes! You can save full Events that you have created on your itinerary straight to your Library. Here's how:
1. Click into edit mode for the Event you would like to save. Do this by pressing the pencil icon on the top-right of the Event box.
2. At the bottom next to "Done Editing" press the three dots and then you can click "Save to Library..."
Click on that and your event will be saved to your Library and you can also find it on the right-hand side of your screen when building an itinerary.