The macro editor is essentially the same whether you are editing a macro in an event, or in a separate macro module. The difference is that when editing a macro in an event, the macro editor runs as a modal dialog, and you must finish editing before you can do anything else. When editing a macro module, the editor runs in a separate window, so you can switch between the macro and (say) a form, just as you can switch between a form and a report.
The screenshot below shows the dialog macro editor. The main part of the dialog (which also appears in the module macro editor) comprises three sections. The upper section shows each of the actions in the macro in order of execution, and has a column into which you can enter a comment; comments are otherwise ignored by Rekall. The bottom-left section shows the macro arguments for the currently selected action; and the bottom-right section displays a brief description of the selected action.
Macro actions are selected by clicking on a row in the upper section. The macro name column changes to a combobox when you click in it, allowing you to set the macro name. Right-clicking on a macro action brings up a popup menu, which allows you to insert and delete actions, and to move actions up and down the list (in case you have got them in the wrong order). Rekall will always put an empty entry at the bottom of the list so that you can append further actions.