You can use a external storage device to transfer the catalog and images to the main computer.
Use the below link to merge the catalog.
Hope this helps.
Thanks for your advice. I do know how to proceed with my import of the catalouge in to my master on the MAC
Set up a specific “On Location” catalog to use whilst traveling. If you save as a template you can use a fresh catalog each time you are on vacation or a business trip. It is then simple to import the entire travel catalog into your master catalog preserving all your editing and metadata.