How do I add CiviCRM Activity attachment to View
I attended a session yesterday at CiviCon (https://denver2015.civicrm.org/sessions/civicrmdrupal-integration-showcase; the slides are up already) about exposing more Civi tables to Views.  

CiviCRM Entity 1.x might display the table you need.  CiviCRM Entity 2.x-dev most definitely will.  (https://www.drupal.org/project/civicrm_entity)  The session slides have lots of details on installation and use.

A sandbox module is also available to expose the Civi tables to Views (https://www.drupal.org/sandbox/markusa/2474103).

The inherent (edited) difference is the sandbox module is just exposing the data to Views. The CiviCRM Entity module will make Civi data available to all of Drupal as entities.