Windows 10 supports a total of four sizes for Start menu tiles: small, medium, wide, and large. One can change the size of a tile by right-clicking on it, selecting Resize, and then clicking one of the sizes.
With default settings, the Windows 10’s Start menu displays three columns of app tiles, if tiles size is set to medium. If you want to see more app tiles on the Start without scrolling down, you need to either reduce the size of tiles or increase of width of the Start menu.
The default width of the Start menu can be easily increased by keeping the mouse pointer at the right-edge of the Start menu and dragging the same towards to the right-edge of the screen. But this method adds another three columns of tiles (medium size tiles) to the Start menu and takes more than half the space on the screen on PCs with 14” or lesser screen size.
Add the 4th column to the Start menu
If you want to add just the 4th column (again, medium size tiles), there is a provision under Settings app to add only the 4th column to the Start menu in Windows 10.
Here is how to add an additional column to the Start menu in Windows 10.
Step 1: Open the Settings app by either clicking Settings on the left side of the Start menu or using Windows logo + I keyboard shortcut.
Step 2: Click on Personalization.
Step 3: Click Start.
Step 4: Turn on the option labeled Show more tiles to add the 4th column to the Start menu.
You can now move existing tiles to the 4th column by dragging and dropping. You can also create custom Start menu tiles.