First off, let’s create a custom function that will extract package piece types:

function my_custom_peice_type_extractor($shipment_id){
    $str_result = "";
    $packages = maybe_unserialize(get_post_meta($shipment_id, 'wpc-multiple-package', true)) ?: array();
    if(is_array($packages) && !empty($packages)){
        foreach($packages as $package){
            $package_quant = (int)($package['wpc-pm-qty'] ?: 1);
            $package_peice_type = $package['wpc-pm-piece-type'] ?: 'Standard Box';
            $str_result .= "{$package_quant} {$package_peice_type}, ";
        }
        $str_result = rtrim($str_result, ', ');
    }
    return $str_result;
}

After creating the function, add custom table header and data on shipments table:

function wpcc_shipment_table_header_action_callback(){
     echo "<th class='no-space='>".__('Piece Type', 'wpcargo')."</th>";
}


function wpcc_shipment_table_data_action_callback( $shipment_id ){
     echo "<td class='no-space='>".my_custom_peice_type_extractor($shipment_id)."</td>";
}


add_action('wpcfe_shipment_table_header', 'wpcc_shipment_table_header_action_callback');
add_action('wpcfe_shipment_table_data', 'wpcc_shipment_table_data_action_callback');