Page title "All Posts" can be changed either in language file in theme_name/languages folder using Poedit software or directly in  wp-content/themes/theme_name/fw/core/type.post.php file (support.post.php),  line 359.  Please search for the text in the document in case the text is not found on this line.

 $title = esc_html__( 'All Posts', 'theme_name' );