alphabet = ["A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"];

let tr = $("<tr></tr>"); // create tr Element with Jquery
for (let i = 0; i < alphabet.length; i++) {

  let td = "<td>" + alphabet[i] + "</td>";
  tr.append(td);
}


/* append tr Element to the end of Table element twenty-five times
and table will have twenty five rows*/
for (let i = 1; i <= 25; i++) {
  $("table").append(tr);
}

table, td {
    border: 1px solid black;
    border-collapse: collapse;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

<div id="myDiv">
  <table>

  </table>
</div>

alphabet = ["A","B","C","D","E","F","G","H","I","J","K"        ,"L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"];

let tr = "<tr>"; // create tr Element with Jquery
for (let i = 0 ; i < alphabet.length ; i++) { 
    
    let td = "<td>" + alphabet[i] + "</td>";
    tr += td;
}
tr += "</tr>";


/* append tr Element to the end of Table element twenty-five times
and table will have twenty five rows*/
for (let i = 1; i <= 25 ; i++) {     
    $("table").append(tr);
}

table, td {
    border: 1px solid black;
    border-collapse: collapse;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div id="myDiv">
        <table>

        </table>
</div>