Figured this one out that’s been bugging me and thought I’d share as there wasn’t anywere I . I always wondered how to make columns in uilayout.operator_menu_enum like the modifier add or Node connection menus… the trick is inserting items in the enum items that have number = 0
i.e.
items = [ ('Column1', 'Column One', 'Column One', '', 0),
('Item1', 'Item One', 'Item One', '', 1),
(... items .. )
('Column2', 'Column Two', 'Column Two', '', 0)...]