Sharing a bank of contacts
You can export a group of contacts.

So first create a group, then add contacts to it. Theres no menuoption for it, but you can rigthclick on the group and select Export vCard-group…

Or you can select desired contacts to export, File -> Export… -> Export vCard-card…

This will give you one vCard-file containing one or more contacts.

Then you can share the vCard file as you wish.