A way to save space in your photo gallery is to place your galleries inside another main gallery.
For example if you have an annual event like an Easter Egg Hunt you can create a main gallery (Easter Egg Hunt) and have sub galleries inside of it (Easter Egg Hunt 2016).
Here is how to create a main gallery and sub galleries.
Inside your Photo Gallery page select Add New Album
Give your album a title and have No Parent Album selected for Parent Album
Select Update and your new album has been created and added to the gallery
To add another album to Easter Egg Hunt, select Add New Album again
Select Easter Egg Hunt for the Parent Album, and give this new album a title
Select update and notice that Easter Egg Hunt now has 1 Sub Album
When you Click on Easter Egg Hunt you will find the new Sub Album of Easter Egg Hunt 2016
From here you only need to add photos to the album. The tutorial on how to add photos to a gallery can be found here.