Hi @Kuronuma,
Do you want to restrict users to view excel file in SharePoint?
You can create unique permissions for an Excel file so that you can restrict specific people to view an excel file regardless of what permissions users have in the library or site.
If the answer is helpful, please click "Accept as Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.