Is there a list of menu shortcut icons?
The quickest way to get the entire list is to use Finder's help and search for "Symbols used in shortcuts" and refer the to the canonical list of symbols. It's also in the user manual for your mac online and I believe is still shipped with all Macs in the box.

Finder contains six icons in its menu bar and safari has a couple more which visually represent a key on the standard keyboard from Apple (most of which do not share the same icon when made as a physical key cap).


Finder: ⌃ ⌥ ⇧ ⌘ ⎋ ↑
Safari: adds two more ↓ and ⇥


So the list of common symbols is pretty complete as follows:


Control: ⌃ (also ctrl or ctl) 
Option: ⌥ (also alt or alternate)
Shift: ⇧
Command: ⌘ (historically the "Apple" key)
Esc: ⎋
Up Arrow: ↑
Down Arrow: ↓
Tab: ⇥


We also have some references on the "meta" side of the site where we talk about how to differentiate between what is printed on the keys and what software draws in the Menu bar (and other places).


Keyboard icons &amp; terminology