JSFiddle - React, Tailwind, and code Playground

HTML

<select id="Number_of_position">              
    </select>   <table id="Positions_names">
    </table>

JavaScript

alpha = "abcdefghijklmnopqrstuvwxyz";

	function hex(a) {
	  // First figure out how many digits there are.
	  a += 1; // This line is funky
	  c = 0;
	  var x = 1;      
	  while (a >= x) {
	    c++;
	    a -= x;
	    x *= 26;
	  }

	  // Now you can do normal base conversion.
	  var s = "";
	  for (var i = 0; i < c; i++) {
	    s = alpha.charAt(a % 26) + s;
	    a = Math.floor(a/26);
	  }

	  return s;
	}

$(document).ready(function(){

    var select = $("#Number_of_position"), table = $("#Positions_names"); 
	 for (var i = 1; i <= 100; i++){
	        select.append('<option value="'+i+'">'+i+'</option>');
	    }

	    select.change(function () {
	        var rows = '';
	        for (var i = 0; i < $(this).val(); i++) {
	            rows += "<tr><td>" + hex(i) + "</td><td><input type='text'></td></tr>";
	        }
	        table.html(rows);
	    });

	});