Cmd + PgUp/Down shortcut to navigate through terminal tabs
Update:
The answer now reassigns Scroll to Top/Bottom to ⌥⌘PageUp and ⌥⌘PageDown.
This leaves Show Previous/Next Tab free to take over ⌘PageUp and ⌘PageDown.



Assuming your OS X runs in English, you can use this one-liner:

defaults write com.apple.Terminal NSUserKeyEquivalents -dict-add 'Scroll to Top' '~@\Uf72c' 'Scroll to Bottom' '~@\Uf72d' 'Show Previous Tab' '@\Uf72c' 'Show Next Tab' '@\Uf72d'


If your OS X runs in a language other than English, modify the command to resemble the exact menu item text for your language.