Where are Saved tiles stored
When you create a new saved tile from the design canvas, it is stored in the design manager Landing Page under the Manage dropdown menu.
From the Manager, you can select an individual tile and either: Delete or Export it
How to Access your Saved Tiles in design view
From the canvas, navigate to the design ribbon and click Saved Tiles
The second tab section will be Saved Tiles.
Drag and drop onto your page