A Copilot Notebook should be used.
While Copilot Pages are excellent for capturing, refining, and sharing specific pieces of content or a single, finalized document, Copilot Notebooks are specifically designed to be an AI-powered project workspace, allowing you to gather, anchor, and iterate on multiple, complex, long-term tasks.
Why Choose a Copilot Notebook
Gather Multiple Conversations: You can add multiple Copilot chat sessions, along with supporting documentation, into one notebook to keep related work organized.
Shared Reference Material: Notebooks allow you to add up to 100 references (Word documents, PDFs, Excel sheets, etc.) and ground your AI conversations in that specific data.
Contextual Continuity: Unlike standalone chat, a notebook retains the context of all the files and chat history you have added, allowing you to ask questions across your gathered materials.
Iterative Work: You can work on a project, leave, and come back to the same notebook to continue building, rather than creating new chats.
Reference:
https://support.microsoft.com/en-us/topic/how-microsoft-365-copilot-notebooks-works-4071d73d-
8bdd-478f-8968-8dc1d7c3d43e