JSFiddle - React, Tailwind, and code Playground

HTML

<div class="layout" style="background: #222222; width: 100%">
    <div>
        <div class="layout layoutbacking">
                <table>
                <tr>
                    <th>
                        header 1
                    </th>
                    <th>
                        header 2
                    </th>
                    <th>
                        header 3
                    </th>
                    <th>
                        header 4
                    </th>
                </tr>
                <tr>
                    <td>
                        data 1
                    </td>
                    <td>
                        data 2
                    </td>
                    <td>
                        data 3
                    </td>
                    <td>
                        data 4
                    </td>
                </tr>
                       <tr>
                    <td>
                        data 1
                    </td>
                    <td>
                        data 2
                    </td>
                    <td>
                        data 3
                    </td>
                    <td>
                        data 4
                    </td>
                </tr>
                       <tr>
                    <td>
                        data 1
                    </td>
                    <td>
                        data 2
                    </td>
                    <td>
                        data 3
                    </td>
                    <td>
                        data 4
                    </td>
                </tr>
            </table>
        </div>
        <div class="layout" >
            <div class="layout layoutbacking">
                    <table>
                <tr>
                    <th>
                        header 1
                    </th>
                    <th>
                        header 2
                    </th>
                   ...

CSS

.layout 
{
	white-space: nowrap; /* this does the trick */    
    overflow: hidden; /* this prevents the grey divs to overflows */
   -moz-border-radius: 15px;
    border-radius: 15px;
    vertical-align: top;
	display: inline-block;
}

.layoutbacking
{
    -moz-border-radius: 15px;
    border-radius: 15px;
    padding: 5px;
	margin: 5px;
    background: #CCCCCC;
}