To enlarge the font size on your device, you can try increasing the screen resolution using an app called LCDDensity.
If you don't already have this app, go to Market/Play Store, search for it using the magnifying glass and download it. It should be free. Install it.
Once the app is downloaded and installed, press the home button ("N") and open the App Drawer (the four-square icon on your home screen). Find LCDDensity and tap it to open it. A pop-up window will appear. Read the information and click "Continue."
A Superuser Request window will appear. Click "Allow."
Select a density that is larger than 160 (160 is optimal, don't go smaller).
Use the drop-down menu to choose the "Reboot method."
Tap "Apply (Restart)."
At this point your device will restart. (If you are using a Nook Tablet wait for it to boot into Nook mode and then power it off, wait 5 to 10 seconds and turn it on and boot into Android.) When your device turns on you should notice a change in the size of the lock screen and shortcuts on the home screen.
Note: Some apps may not work when the LCD density is set to anything but 160. Warning: Changing the LCD density could cause major issues with your device.