I'd be more than happy to assist you. When you connect your Galaxy Note to your computer, look at the screen on your Note. It may be prompting you to choose between "Charge only" or "USB Disk". In this instance you'd want to select USB disk. Verbiage may very slightly but the general concept is the same.
If that still doesn't work, try a different USB port on your computer.
If that still doesn't work I would restart the computer and tablet.
If that still doesn't work, your last choice is more of a workaround but you could essentially download two pieces of software depending on which you prefer.
One is called Kies Air (not to be confused with just Kies). This a Samsung software you can get from the Google Play store, or it may be preloaded on your Note. This will turn your Note into a server. When run it will give you an IP address and tell you to launch this site from your browser. For example, Kies air on your tablet would say:
Go to: http://192.168.1.55 from your web browser.
You would then launch your computer's web browser and browse that site, then you have full access to your phone/tab, text messages, call log, photos, ability to download and transfer information, or upload direct to your note (documents, etc).
The key is both devices must be on the same WiFi network when you run Kies air for it to work.
Lastly, everyone's favorite and is a must have for anyone who hates hooking up a USB cable to transfer photos, documents, etc.
Dropbox. Dropbox is a Cloud based storage. You download Dropbox for your computer and it creates a new Drive called Dropbox. You just drop files there and it remains in sync with other devices running Dropbox. So you would install Dropbox app on your Note, then upload or download files between the two. Never needing a USB cable.