JSFiddle - React, Tailwind, and code Playground

HTML

<input type="file" id="fileUpload" />
<input type="button" id="upload" value="Upload" onclick="UploadProcess()" />
<br/>

<div id="ExcelTable"></div>

<script src="https://cdnjs.cloudflare.com/ajax/libs/xls/0.7.4-a/xls.js"></script>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/xlsx/0.13.5/jszip.js"></script>
<script type="text/javascript">
    function UploadProcess() {
        //Reference the FileUpload element.
        var fileUpload = document.getElementById("fileUpload");
 
        //Validate whether File is valid Excel file.
        var regex = /^([a-zA-Z0-9\s_\\.\-:])+(.xls|.xlsx)$/;
        if (regex.test(fileUpload.value.toLowerCase())) {
            if (typeof (FileReader) != "undefined") {
                var reader = new FileReader();
 
                //For Browsers other than IE.
                if (reader.readAsBinaryString) {
                    reader.onload = function (e) {
                        GetTableFromExcel(e.target.result);
                    };
                    reader.readAsBinaryString(fileUpload.files[0]);
                } else {
                    //For IE Browser.
                    reader.onload = function (e) {
                        var data = "";
                        var bytes = new Uint8Array(e.target.result);
                        for (var i = 0; i < bytes.byteLength; i++) {
                            data += String.fromCharCode(bytes[i]);
                        }
                        GetTableFromExcel(data);
                    };
                    reader.readAsArrayBuffer(fileUpload.files[0]);
                }
            } else {
                alert("This browser does not support HTML5.");
            }
        } else {
            alert("Please upload a valid Excel file.");
        }
    };
    function GetTableFromExcel(data) {
        //Read the Excel File data in binary
        var cfb = XLS.CFB.read(data, {type: 'binary'});
        var workbook =...