SO-73840608

by David Thomas

HTML

<button id="btn1">Add</button>
 <table id="tab"></table>

CSS

td {
  min-height: 1em;
  min-width: 1em;
}

td[id]::before {
  content: attr(id);
}

JavaScript

const tab = document.getElementById("tab");
const btn1 = document.getElementById("btn1");

btn1.addEventListener('click', () => {
  let row = tab.insertRow(-1);

  for (let i = 0; i <= 15; i++) {
    let c = row.insertCell(i);

    c.id = `R${++row.rowIndex}C${++c.cellIndex}`;
  }
});