There is not a way to refer to data from other documents, I’m sorry to say. This is due to technical reasons, not business ones. Basically, it’s a hard feature to implement. This is partly due to what @telenieko mentions (refreshing the view), and partly because Grist currently lacks any kind of function that can create and populate a set of rows (as opposed to populating a single cell).
What people have done is to copy data from a table in one Grist doc into a table in another. As long as the copying is one-directional, and there is a simple rule for when to do it (e.g. daily), it’s not very difficult to automate, and can be done with Zapier, or some other integrator services, or a custom script that uses the API.