The closest thing to what you're asking for is Azure AD Reporting API for Sign-in activity:
https://docs.microsoft.com/en-us/azure/active-directory/active-directory-reporting-api-sign-in-activity-reference
Note that, at this time, this is only available in the Azure AD Graph, not the Microsoft Graph.
https://graph.windows.net/contoso.com/activities/signinEvents?api-version=beta
You can filter by user and/or appDisplayName.
https://graph.windows.net/contoso.com/activities/signinEvents?api-version=beta&$filter=appDisplayName eq 'Office 365'
Doing some quick testing by launching the Office Portal, Outlook, Sharepoint, etc, I saw the following entries:
- Office 365
- O365 Suite UX
- Office 365 Exchange Online
- Office.com
- Office 365 SharePoint Online
- Skype Web Experience On Office 365
You'll need to do some experimentation to see if you can see entries for everything your interested in. I don't think you'll get entries down to the granularity level you seem to be interested (Word, Excel, PowerPoint).