Modo supports customisable Layouts displayed in the form of Tabs at the top of the UI.
Adding a new Layout is as easy as clicking the small + symbol on the right of the Tab pane.
Removing a Tab is a little more obtuse, it requires a few clicks in the Menus.
As the Tabs represent Layouts you go to the Layout menu and select Delete… to open the Delete Layout window.
From there you have a menu dropdown and you choose the Tab/Layout you wish to remove.