How do I make a table scrollable

You need to declare a height first, else your table will expand to the according width of its content.

table{
   overflow-y:scroll;
   height:100px;
   display:block;
}

EDIT: after clarifying your problem I edited the fiddle: check out this Example or that way. It's rather hacky and not guaranteed to work crossbrowser but might work for your case.


You can wrap the table with a parent div and make him scrollable as scoota269 advised:

.div_before_table {
    overflow:hidden;
    overflow-y: scroll;
    height: 500px;
}

And to keep the table header sticky you can add a fixed class:

.th.fixed {
    top: 0;
    z-index: 2;
    position: sticky;
    background-color: white;
 }

table {
  font-family: arial, sans-serif;
  border-collapse: collapse;
  width: 100%;
}

td,
th {
  text-align: left;
  padding: 8px;
}

tr:nth-child(even) {
  background-color: #ddd;
}


/* The scrollable part */

.scrollable {
  height: 150px;
  overflow-y: scroll;
  border-bottom: 1px solid #ddd;
}

th {
  position: sticky;
  background-color: white;
  z-index: 2;
  top: 0;
}
<div class="scrollable">
  <table>
    <tr>
      <th>Company</th>
      <th>Contact</th>
      <th>Country</th>
    </tr>
    <tr>
      <td>Alfreds Futterkiste</td>
      <td>Maria Anders</td>
      <td>Germany</td>
    </tr>
    <tr>
      <td>Centro comercial Moctezuma</td>
      <td>Francisco Chang</td>
      <td>Mexico</td>
    </tr>
    <tr>
      <td>Centro comercial Moctezuma</td>
      <td>Francisco Chang</td>
      <td>Mexico</td>
    </tr>
    <tr>
      <td>Centro comercial Moctezuma</td>
      <td>Francisco Chang</td>
      <td>Mexico</td>
    </tr>
    <tr>
      <td>Ernst Handel</td>
      <td>Roland Mendel</td>
      <td>Austria</td>
    </tr>
    <tr>
      <td>Island Trading</td>
      <td>Helen Bennett</td>
      <td>UK</td>
    </tr>
    <tr>
      <td>Laughing Bacchus Winecellars</td>
      <td>Yoshi Tannamuri</td>
      <td>Canada</td>
    </tr>
    <tr>
      <td>Magazzini Alimentari Riuniti</td>
      <td>Giovanni Rovelli</td>
      <td>Italy</td>
    </tr>
  </table>
</div>

You can't do that with a table. Wrap the table with a div a give it something like:

div.wrapper {
    overflow:hidden;
    overflow-y: scroll;
    height: 100px; // change this to desired height
}