Yes, you can create multiple registries/giftlists for different occasions.
DESKTOP:
To add a separate registry, simply sign in to your account and click the person icon from the top right-hand side of the page. Then tap CREATE NEW GIFT LIST.
MOBILE WEB BROWSER:
To create a new registry using your mobile web browser, simply login to your account, select the menu button (the three horizontal lines in the upper left corner and click on the top toggle menu that will read (Name of Registry member currently has). When that drop menu opens, you will see the option CREATE NEW GIFT LIST.
APP:
To add a separate registry from your app, simply sign in to your account and go to your My Gifts tab. Click the drop-down arrow where it reads My Registry TYPE, then tap Create New Gift List.