My question is similar to a question previously posted but never really answered here:
Disable GUI, graphics devices in R
I do not like the R tcltk popups fo
Dirk provides ways to avoid the menus altogether, but to answer your question as posed, I think you want
options(menu.graphics=FALSE)
I tracked this option down by finding the class of objects returned from help (it's help_files_with_topic), scanning utils:::print.help_files_with_topic and finding the line
menu(txt, title = gettext("Choose one"), graphics = getOption("menu.graphics"))