When using ALT+SPACE_BAR the window menu of Google Chrome pops. but I was wondering if the same can be don for showing a tab's menu with Reload, Duplicate, New Tab, Pin Tab, etc. Is there a shortcut for this?
There isn't one for the menu I believe, however there are shortcuts for some of the separate actions though.
I suggest you look here: http://www.google.com/support/chrome/bin/static.py?page=guide.cs&guide=25799&topic=28650