When you want to send your contacts entries, you can combine them all into one file or you can send separate vCard files.
To set the transfer type, from the Contacts app, tap the Menu icon (at the upper-right corner of the screen) > Settings > Transfer type.
Send as one file: This setting combines all of your contacts into one file. It allows a faster transfer, but some devices can't receive contact information sent using this option.
Send separately: This setting sends each contact as a separate vCard file. It allows all devices to receive your files.