You can edit/replicate the Rooms / Dining submenu content using the Vamtam Beaver Builder, as shown on the screenshots below:

1. Navigate to Appearance > Menus > Main Menu > mouse hover the Rooms / Dining menu > click the Mega Menu blue button:

2. You can change the template in the VamTam Builder Layout widget:

3. Navigate to VamTam Builder > Saved Rows > Dining Menu / Rooms Menu > click the Vamtam Builder link to edit the template:

Please check this guide for more details: Guide to Vamtam Beaver Builder