I wouldn’t create a separate table for LastCall and I would reduce the redundant fields. You could take tblNewNumbers and call it Contacts and add a ContactId IDENTITY column that will serve as a PRIMARY KEY to establish relationships.

Then I would create a CallLog table with a callLogId, contactId and callDate. You can create one stored proc to do the inserts and you can create another stored proc that takes contactId as input and returns the MAX(callDate) for the contactId.