One of the longest of latex.tcl's submenus contains the entire Greek alphabet, including both lower and upper-case letters (hold down the <OPT> key while the Greek submenu is down to see the latter), plus a handful of lower-case ``italicized'' letters (\varepsilon, \vartheta, \varpi, \varrho, \varsigma, and \varphi). To type a Greek command at the keyboard, press <CTL M> <LETTER>, where <LETTER> is the same key assigned to that letter by the Macintosh Symbol font. See the file latex_bindings.tex for a useful summary.
NOTE: There are two Greek submenus. While one is down, press a modifier key (such as <OPT>) to see the alternate menu.