JSFiddle - React, Tailwind, and code Playground

HTML

<div class="board"></div>

CSS

.cell {
    width: 30px;
    height: 30px;
    outline: 1px solid black;
    display: inline-block;
    vertical-align: top;
}
.row {
    background-color: red;
}

JavaScript

$(function() {
    var boardHTML = '';
    
    for (var r = 0; r < 2; r++) {
        var row = '<div class="row">';
        
        for (var c = 0; c < 5; c++) {
            row += '<div class="cell"></div>';
        }
        
        row += '</div>';
        boardHTML += row;
    }
    
    $('.board').append(boardHTML);
});