This feature was suggested for OperaGX, but I am asking the same for Opera for Windows. Even IE has this option, and it saves a lot of time needed to go to the download directory every time to delete the files you only need to open for a short time. I usually open excel and word files just to check some info on them and then I don't need them anymore.
So the idea is to add the option of opening the file (with the appropiate application, not inside the browser) to the automatically download every-single-file we click on, and then we could choose what we want to do with the file.
Also I frequently download epub with DRM (.ascm files), and other browsers such as IE and Chrome allows to open them directly on Adobe Digital Editions, making the process soooo smooth and simple...please make our life easier!!!