It can also happen if you are using a HiDPI screen, regardless of your monitor size. Judging from your screenshot, your resolution appears to be extremely large. Though not related to your case, it’s worth mentioning that high-end smartphones have a very large resolution packed into a small screen, this results in fonts becoming tiny while the widgets are big. Even here on Bitcointalk the reply button is small on an iPhone.
On Windows 10 go to Settings —> Display to change the DPI to the normal amount, 96DPI. It may be behind “Advanced Options”. I can’t post a screenshot of it while on mobile though, so I will make one later.
EDIT: It's actually under Display --> Scale and Layout, and make sure it's at 100% to make it use normal DPI.