Doubt in table generation in excel file

I have a Javascript function that generates the table of a page in an Excel worksheet. Here is the code below:

function montaExcel(){
    var tab_text = "<table><tr><td><img src='http://xxx.xxx.xxx.xxx/images/layout/logo.jpg'></img></td></tr><tr><td style='font-size: 20px'>"+$('#comboUnidades option:selected').text()+"</td><td style='font-size: 20px'>"+$('#txtData').val()+"</td></tr><tr><td></td></tr></table>";

    tab_text=tab_text+"<table border='2px'><tr bgcolor='#CCCCCC'>";
    var textRange; var j=0;
    tab = document.getElementById('tblAcompanhamentoDiario'); // id of table

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

    tab_text=tab_text+"<table><tr><td></td></tr><tr><td colspan=8>"+$('#txtRodape').html()+"</td></tr></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
    tab_text= tab_text.replace(/<input[^>]*>|<\/input>/gi, ""); // reomves input params

    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("Save As",true,"Acompanhamento_Diario.xls");
    }  
    else                 //other browser not tested on IE 11
        sa = window.open('data:application/vnd.ms-excel,' + encodeURIComponent(tab_text));  

    return (sa);
}

However, the images are overlapping cells, like logo.jpg (I made bold in the above code).

How can I improve this? Any suggestions?