The "easiest" way, IMO, is to add the contacts to your Gmail account and then sync with the tablet. Or add them to your Verizon contact list and sync (I've found Google to be more reliable though).
In the Contacts app (may be called People) there is an import/export feature (tap the three dots on the top right of the screen when you open your contact list) but I've never used that to add contacts. I typically add them on my phone, or in Gmail on the computer, and it all syncs when I log into Google.
