table { 
    border-collapse: separate; 
    border-spacing: 0 10px; 
    margin-top: -10px; /* correct offset on first border spacing if desired */
}
td {
    border: solid 1px #000;
    border-style: solid none;
    padding: 10px;
    background-color: cyan;
}
td:first-child {
    border-left-style: solid;
    border-top-left-radius: 10px; 
    border-bottom-left-radius: 10px;
}
td:last-child {
    border-right-style: solid;
    border-bottom-right-radius: 10px; 
    border-top-right-radius: 10px; 
}