could I install Ubuntu on galaxy note using Nexus 7 Desktop Installer?
No, the installer only supports the 8GB and 16GB Nexus 7 devices.
The key aspect to running Ubuntu on tablet hardware is whether there exists an accelerated Xorg driver for that hardware available for Ubuntu. Many SoC vendors do not provide such a driver, since it is a significant amount of work, and they are already supporting the Android graphics stack (SurfaceFlinger).
Without this driver, it is unlikely for Ubuntu to run well (or at all) on the device.
I led the team that wrote this installer and created the image, so that's my source of information for you. :)
I am currently using a Samsung Galaxy Tab 2 (7.0) Android tablet 'alongside' Ubuntu (SSH, tethering, etc.), but I instead chose the Google (ASUS) Nexus 7 to actually test install of Ubuntu. It being the 'reference platform'.
My understanding (still limited) is that the 'Nexus 7 Installer' replaces Android, while using the Nexus 7 'stock' ROM and any other additional elements to run.
You may need to investigate some of the other more generic approaches (dual OS, replacement ROM, etc.).
You should also checkout: LinuxonAndroid >> Working Devices