Sharepoint - Combining multiple lists into one
You can export the lists in Excel sheets. Combine them and create another list using the combined excel sheet. This way will only allow you to combine data upto that particular point of time. i.e, its not dynamic.
You can combine lists using a Data view web part creating a new linked resource. Refer this blog for details. And afterwards you can export this combined Data View web part using javascript. Find all the details here for exporting. Exporting from a Data View web part would be dynamic and real time.
Good Luck .