Due to the increase of high-resolution displays finally starting to grow in the PC market, Microsoft has updated Windows 8.1 to support these high-DPI displays. And even though the operating system includes new tile sizes to allow more apps and links in the Start screen, Windows 8.1 also come with a new feature called Show More Tiles.
This new feature, Show More Tiles, only appears on high-density displays and it let users add extra rows of tiles to the Windows 8.1 Start screen. However the option also shows up on the new small devices with resolutions of 1280 x 800 or similar. If you know your screen sizes, you know that this isn’t exactly high-resolution, but apparently Microsoft is taking into account the amount of pixels per inch, plus the total screen resolution to enable Show More Tiles.
I have an HP 2311x monitor with a screen resolution of 1920×1080 (1080p) and the feature isn’t enabled, but on the Acer Iconia W3 with a resolution of 1280×800 (720p) the option is there, just as an example.
You can check whether the Show More Tiles is available on your Windows 8.1\RT device by going to the Start screen, bringing the Settings menu, using the +i keyboard shortcut, and clicking Tiles. If the Show More Tiles is in the menu, then you can increase the number of rows in Start.
This is a nice addition to take advantage of the new high-resolution displays that we are starting to see on many devices (e.g., tablets, ultrabooks, laptops, and desktops). Previously the only way to add more tile rows to Start was by modifying the Windows Registry, but this made it really difficult to everyday users to take advantage of this capability.
Source Winsupersite and image