The short answer, no, not in Moodle. The issue doesn't lie with Moodle, it's a limitation of the browser technology and the interaction with proprietary software. It is only fairly recently that we have been able to read, but not edit, PDFs in a browser. I can't see the Dark Side, for example, opening up their Office docs code bases sufficiently to allow the development of browser plugins to make that happen. As for the browser, they are written for wysiwyg formatted documents, html, but proprietary type documents carry their own formatting, which means only something that can read that formatting can open it. To add in code to allow a browser to read, then edit, those documents would likely make the browser so big it would need a blu-ray disk to install it.
There is a setting in the File format that does force download. Added to that, in Chrome, for example, this is set in Settings > Advanced > Downloads where you can set the browser's automatic download folder and there is also a switch to prompt "Ask where to save each file before downloading" which is always on for me. From memory, Firefox
uses Options > Downloads settings, I don't know what other browsers do.