JSFiddle - React, Tailwind, and code Playground

JavaScript

function groupBy(array, f) {
    var groups = {};
    array.forEach(function (o) {
        var group = JSON.stringify(f(o));
        groups[group] = groups[group] || [];
        groups[group].push(o);
    });
    return Object.keys(groups).map(function (group) {
        return groups[group];
    })
}

var arr = ['ar', 'ar', 'ar', 'ar', 'at', 'br', 'de', 'de', 'de',
    'jp', 'jp', 'us', 'us', 'us', 'us', 'us', 'us'];

arr = groupBy(arr, function (item) {
   return [item];
});

var table = document.createElement('table');
table.style.border = '1px solid black';

for (var i = 0; i < arr.length; i++) {
    var tr = document.createElement('tr');
    table.appendChild(tr);
    var td_dmxn = document.createElement('td');
    td_dmxn.style.border = "1px solid black";
    td_dmxn.innerHTML = arr[i];
    td_dmxn.style.textAlign = "center";
    var row = arr[i],
        prevRow = arr[i - 1];
    if (prevRow && row === prevRow) {
        td_dmxn.innerHTML = '';

    } else {

    }
    $(tr).append(td_dmxn);
}
document.body.appendChild(table);