Source

File: wp-admin/includes/class-wp-list-table.php

protected function get_table_classes() {
		$mode = get_user_setting( 'posts_list_mode', 'list' );

		$mode_class = esc_attr( 'table-view-' . $mode );

		return array( 'widefat', 'fixed', 'striped', $mode_class, $this->_args['plural'] );
	}