This screen is a list of all your Cards that have been created. It is very helpful in locating your existing Cards since the Library Search does not display Cards. You are able to filter the list by different Orgs, by the different Card types, or even search the list by a Card title.
The table list features the Card's title, how many connections it has, the type of template it is, when it was last updated, and whether the Card is active or not.
At the top right of the screen, you have the ability to create a Card. It is not recommended to create a Card from this screen, because it would not live in a Deck.
If you check the box next to a Cards title, you will notice that the Add/Remove Connections button at the top right of the screen becomes active. If you click on that button, a modal will appear, allowing you to add or remove a connection from that Card. If you check the box next to the word Title in the table list, all of the Cards will become checked and you can then add or remove connections to all of your Cards.