How do I translate a view's "Menu tab"
The first steps when dealing with translations, particularly with user entered strings like Views Tabs labels, is to clear the cache and visit the page showing the string in question but make sure you visit in a language other than English! 

The visit to that page with the interface in another language will trigger Drupal to refresh the Translate Interface list, and you should be able to find the new string when doing a search there (admin/config/regional/translate/translate). 

Remember that the Translate Interface search is case sensitive! You have to enter "My Articles" and not "my articles" or any other case style. 

If that search still isn't giving you any results, it may be you're missing a module that enables those strings to be included in translations. Make sure you have "String translation" or perhaps even "Variable translation" enabled. 

If you've just enabled "String translation", similar to above, visit the page in another language then search for the string in Translate interface.