Now that you have defined the Insert Section action and the Insert Table action, you can add them to the toolbar. You can configure additional toolbars on which to add your custom actions.
The first thing to check is that the toolbar Author custom actions 1 is displayed when switching to the Author mode: right click in the upper part of application window, in the area that contains the toolbar buttons and check if Author custom actions 1 in the displayed menu if it is unchecked.