body {
    background: grey;
   


}

#ejemplo{
    overflow:auto;
    height:400px;
    width:100%;
}


thead {
     
    height: 400px;
    display: inline-block;
    width: 100%;
    overflow: auto;
}


tbody {
    height: 400px;
    display: inline-block;
    width: 100%;
    overflow: auto;
}