shortcut for accessing tab menu in Google Chrome
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
Hitting F6 twice worked for me. I used this to then access the tab's right click menu (Shift+F10) to be able to access the new tab grouping features in Chrome entirely through keyboard shortcuts.
Shift + F6 + (release F6 while still holding Shift) F10