As solid as Windows 10 is as an OS all-around, Microsoft made some design decisions with it that have annoyed its faithful customer base (unless you feel like you have no choice but to use Windows, of course). Privacy has been at the forefront of complaints, with the OS tracking us like never before, but more noticeably annoying has been the bloat the OS ships with.
It used to be that after unpacking that brand-new laptop, any bloatware found on the system would be from the vendor itself. That could include things like that vendor's own control panel, but also things like third-party software applications. Usually, if Microsoft had a "bloat" presence, it was related to Office, and that's about it.
In a build that will become final at some point in the first-half of 2019, Microsoft will be deploying a feature (now seen in build 18262 on the Windows Preview fast ring) that will allow users to uninstall more of the default applications that ship with the OS. Currently, you can uninstall many of these, but many more exist that fade out the "Uninstall" option to the chagrin of anyone who simply doesn't something pointless (to them) like "3D Viewer" installed.
This forthcoming build will allow users to uninstall that very app, as well as Calculator, Calendar, Groove Music (which has really limited use nowadays, since Groove as a service no longer exists), Mail, Movies & TV, Paint 3D, Snip & Sketch, Sticky Notes, and Voice Recorder.
If you don't want to wait an unknown number of months to get rid of that bloat, you're not out of luck. If you launch PowerShell with administrator rights, you can forcibly remove apps with this command:
Get-AppxPackage *3dviewer* | Remove-AppxPackage
That command would of course remove 3D Viewer, where the asterisks denote wildcards. Other examples could be done with *zune* (Groove), *sticky*, *photos*, *paint*, and so on. If you are not sure what to type for a certain app, all you need to do is launch it, then open Task Manager and inspect its properties, like this:
In this case, "WindowsCalculator" would work in that statement, or *Calc*, as it fits the wildcard. You of course don't want to use queries with wildcards that are so generic, it'd uninstall some other similarly named application. If you want to truly clean up your new Windows 10 install, you can uninstall upwards of 30 of these apps, assuming that some include the bloatware games (Cooking Fever, Dragon Mania, etc) Microsoft dumps on us.
Microsoft's move here doesn't add everything that can be actually removed to the list, so if you really want to clean up, this build isn't going to cater well enough to you. Fortunately, Microsoft hasn't held back the functionality for you to be more thorough on your own.