This started recently I think, and only seems to be an issue in chrome. The table-responsive class is supposed to contain the table, for scrolling when there's overflow, but in chrome the td/th elements are flowing out of the container.
Here is the HTML:
<div class="compact card-columns">
<div class="card bg-light mb-3" style="max-width: 18rem;">
<div class="card-header">Header</div>
<div class="card-body">
<h5 class="card-title">Light card title</h5>
<p class="card-text">Some quick example text to build on the card title and make up the bulk of the card's content.</p>
</div>
</div>
<div class="card bg-light mb-3" style="max-width: 18rem;">
<div class="card-header">Header</div>
<div class="card-body">
<h5 class="card-title">Light card title</h5>
<p class="card-text">Some quick example text to build on the card title and make up the bulk of the card's content.</p>
</div>
</div>
<div class="card bg-light mb-3" style="max-width: 18rem;">
<div class="card-header">Header</div>
<div class="card-body">
<div class="table-responsive">
<table class="table">
<thead>
<tr>
<th scope="col">#</th>
<th scope="col">Heading</th>
<th scope="col">Heading</th>
<th scope="col">Heading</th>
<th scope="col">Heading</th>
<th scope="col">Heading</th>
<th scope="col">Heading</th>
<th scope="col">Heading</th>
<th scope="col">Heading</th>
<th scope="col">Heading</th>
</tr>
</thead>
<tbody>
<tr>
<th scope="row">1</th>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
</tr>
<tr>
<th scope="row">2</th>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
</tr>
<tr>
<th scope="row">3</th>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
<td>Cell</td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
</div>
And the CSS:
td, th {
position: relative;
}
I've also reproduced it here in a pen:
