If your designer wants to have table rows floating one above another, with some space between, and having rounded borders, follow this:

:root {
    --border-radius: 5px;
}

table {
    background-color: gray;
    border-collapse: separate;
    border-spacing: 0 2px;
}

tr {
    background-color: white;
}

td:first-child {
    border-bottom-left-radius: var(--border-radius);
    border-top-left-radius: var(--border-radius);
}

td:last-child {
    border-bottom-right-radius: var(--border-radius);
    border-top-right-radius: var(--border-radius);
}
  • Border-Collapse makes rows separated from each other, or not depending on value
  • rows background color should be different from table background color
  • border radius should be set just for left and right td elements