If you, after converting arcmenu.dat, want to get rid of (Mame) on each
mame entry you can use a text editor (e.g. edit) then choose "search"
and then "replace".  In the "find what" section you should type in
(without the quotes) ' (Mame)' and then leave the "Replace With" section
blank. Then press "Change all" and you should be OK.

Repeat for other entries. (If any)