Change the screen size and dpi Is there a way to make Android think it has a different screen size and dpi than what was programmed in its factory settings?

I'm asking because we bought a 7-inch tablet recently, and its interface is too large for a 7-inch tablet. I installed System Info Droid and it confirmed what I suspected: The tablet thinks its screen is 4.86 inches with 192dpi.

Is there a way to fix this and tell it its screen is 7 inches and 133dpi?

The tablet is Genx GX7-3GS running Android 4.2.2.
You can change. First ROOT your device. 
Using file manager go to your root directory. Open folder named system. In that open file named build.prop using text editor. 
Search for option called lcd_display= (after equals to enter your default DPI value) and save file.
Now reboot. Done.