Edit in JSFiddle

table {
	border-collapse: collapse;
	border-spacing: 0;
}

button {
    width: 50px;
    height: 40px;
    background: #fff;
    border: 4px solid #000;
    cursor: pointer;
    margin: 0px;
}

td {
    margin: 0px;
    padding: 0px;
}

div {
    text-align: center;
}

.wrapper, table {
    margin: 20px auto;
}