NetworkDatabase is the structure responsible for storing all NetworkPrefabs and NetworkEvents databases into a unique internal database. Each NetworkManager and NetworkEventsManager can target just one database per game.
The selected database appears on the top of NetworkManager object.
To modify the current Database you shall click on the eye icon close to the "Click to modify" message.
A new "Network Database" window shall appear.
Click on the eye icon
Network DataBase Window
Creating DataBase
To create a new Database you shall fill in the Database Name field and press "Create"
A new database shall appear on the last record on the listed database.
Deleting DataBase
Locate the database that you wish to delete
Click on the remove button on the left side of the database name
Changing DataBase
Locate the database that you wish to select
Click on the select button on the right side of the database name