It depends on your theme if it has any basic table related styling included or not, most themes does some doesn’t.
Here is mine
table {
overflow:hidden;
border:1px solid #d3d3d3;
background:#fefefe;
width:70%;
margin:5% auto 0;
-moz-border-radius:5px; /* FF1+ */
-webkit-border-radius:5px; /* Saf3-4 */
border-radius:5px;
-moz-box-shadow: 0 0 4px rgba(0, 0, 0, 0.2);
-webkit-box-shadow: 0 0 4px rgba(0, 0, 0, 0.2);
}
th, td {padding:18px 28px 18px; text-align:center; }
th {padding-top:22px; text-shadow: 1px 1px 1px #fff; background:#e8eaeb;}
td {border-top:1px solid #e0e0e0; border-right:1px solid #e0e0e0;}
tr.odd-row td {background:#f6f6f6;}
td.first, th.first {text-align:left}
td.last {border-right:none;}
/*
Background gradients are completely unnecessary but a neat effect.
*/
td {
background: -moz-linear-gradient(100% 25% 90deg, #fefefe, #f9f9f9);
background: -webkit-gradient(linear, 0% 0%, 0% 25%, from(#f9f9f9), to(#fefefe));
}
tr.odd-row td {
background: -moz-linear-gradient(100% 25% 90deg, #f6f6f6, #f1f1f1);
background: -webkit-gradient(linear, 0% 0%, 0% 25%, from(#f1f1f1), to(#f6f6f6));
}
th {
background: -moz-linear-gradient(100% 20% 90deg, #e8eaeb, #ededed);
background: -webkit-gradient(linear, 0% 0%, 0% 20%, from(#ededed), to(#e8eaeb));
}
/*
I know this is annoying, but we need additional styling so webkit will recognize rounded corners on background elements.
Nice write up of this issue: https://www.onenaught.com/posts/266/css-inner-elements-breaking-border-radius
And, since we've applied the background colors to td/th element because of IE, Gecko browsers also need it.
*/
tr:first-child th.first {
-moz-border-radius-topleft:5px;
-webkit-border-top-left-radius:5px; /* Saf3-4 */
}
tr:first-child th.last {
-moz-border-radius-topright:5px;
-webkit-border-top-right-radius:5px; /* Saf3-4 */
}
tr:last-child td.first {
-moz-border-radius-bottomleft:5px;
-webkit-border-bottom-left-radius:5px; /* Saf3-4 */
}
tr:last-child td.last {
-moz-border-radius-bottomright:5px;
-webkit-border-bottom-right-radius:5px; /* Saf3-4 */
}
Add it to your style and it will look something like this
https://wptheming.com/2011/01/simple-table-css3/
some other resources
https://coding.smashingmagazine.com/2008/08/13/top-10-css-table-designs/
https://www.csstablegenerator.com/
Good luck