Comment transformer un tableau en un tableau responsive lisible sur des petits écrans

@media (max-width: 500px) {

/* table + tbody are blocks */
#mytable, #mytable tbody {
display: block;
width: 100%;
}

/* each row becomes table */
#mytable tr {
display: table;
margin-top: 20px;
width: 100%;
border-spacing: 5px 0;
}

/* each cell becomes a row (of the row that had become a table)  */
#mytable tr td {
display: table-row;
width: 100%;
}
}