Microsoft Edge is continually updated with new features and fixes. The browser is available on multiple platforms, including Linux, and Microsoft has several preview channels set up where it first tests new capabilities with a subset of enthusiasts and developers before generally rolling them out to the public. An example of this is the company exploring the option to replace the HTTPS lock icon with a down arrow because the current icon could mislead users into believing that a site is secure.
Now, it seems that Microsoft is working on deepening Edge's integration with its Office apps on the web. Reddit user u/Leopeva64-2 has noted that Edge Canary's latest build has a new option in the tab's context menu. Essentially, if you right-click on a tab in the window, you'll get an updated context menu which will now feature an option called "New Office tab". Nested inside this will be more granular options such as "Word document", "PowerPoint presentation", and "Excel workbook". You can view a screenshot of its current implementation below:
Clicking on any of the nested options will open the associated Office web app synced with your OneDrive account in the browser. While there is currently no toggle to disable the presence of this particular configuration in the tab's context menu, it wouldn't be surprising to have one if this feature does get rolled out to the Stable channel eventually.
It is important to note that this capability is still being tested in preview channels so there is no guarantee that it will make its way to the general public. Furthermore, its current availability is also a part of Microsoft's controlled rollout strategy for Edge, so not everyone even on Edge Canary will have it yet. We don't have it on our test devices running Edge Canary either.