Call logs tab
This tab displays the history of all of your calls. From here you can call or contact any of the entries. To delete all of the Call logs entries at once, tap and hold any entry, tap Clear all, then tap the OK icon to confirm you want to delete them.
NOTE
You can also selectively delete entries from the Call log. Tap
the Menu Key 
> Clear > tap
the checkboxes to the left of the entries to delete > Clear > OK.