A viewing key manager is an object provided by Griptape to manage viewing keys in a centralized way. This is definitely a helper utility and is not necessary for you to manage viewing keys using this API. One advantage of using this API is that it integrates directly with the contracts API.
Here we have some examples to better understand how the API works.
It's important to mention that when interacting with contracts, viewing keys exposed by the Contextshould be registered using the viewingKeyManager in order for queries to have the viewing key available.