如何使用.xls格式使用JavaScript一次下载多个表

Question

I am currently trying to export multiple tables at once using a PHP & Javascript.

I did implement the function but it's only exporting one table at a time.

https://imgur.com/a/htfc3UM

As you can see it's only exporting the first table only.

Here is the JS code

<script>
    function ToExcelReport(){
    var tab_text="<table border='2px'><tr bgcolor='#FFFFFF'>";
    var textRange; var j=0;
    tab = document.getElementById('testTable'); //id of table

    for(j = 0 ; j < tab.rows.length ; j++){     
        tab_text=tab_text+tab.rows[j].innerHTML+"</tr>";
    }

    tab_text=tab_text+"</table>";
    tab_text= tab_text.replace(/<A[^>]*>|<\/A>/g, "");//remove if u want links in your table
    tab_text= tab_text.replace(/<img[^>]*>/gi,""); //remove if u want images in your table


    var ua = window.navigator.userAgent;
    var msie = ua.indexOf("MSIE "); 

    if (msie > 0 || !!navigator.userAgent.match(/Trident.*rv\:11\./)){
        //if Internet Explorer
        txtArea1.document.open("txt/html","replace");
        txtArea1.document.write(tab_text);
        txtArea1.document.close();
        txtArea1.focus(); 
        sa=txtArea1.document.execCommand("SaveAs",true,"Sample.xls");
    } else{
        //other browsers
        sa = window.open('data:application/vnd.ms-excel,' + encodeURIComponent(tab_text));  
    }

    return (sa);
}
        </script>

I would like to know, How I could fix my code so that I'll be able to export all the tables at once.