diff -u b/core/includes/theme.inc b/core/includes/theme.inc
--- b/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -1230,28 +1230,12 @@
     }
   }
 
-  // Add the 'empty' row message if available.
-  if (empty($variables['rows']) && isset($variables['empty'])) {
-    $header_count = 0;
-    foreach ($variables['header'] as $header_cell) {
-      if (is_array($header_cell) && isset($header_cell['colspan'])) {
-        $header_count += $header_cell['colspan'];
-      }
-      else {
-        $header_count++;
-      }
-    }
-    $variables['rows'][] = array(array(
-      'data' => $variables['empty'],
-      'colspan' => $header_count,
-    ));
-  }
-
   // Build an associative array of responsive classes keyed by column.
   $responsive_classes = array();
 
   // Format the table header:
   $ts = array();
+  $header_columns = 0;
   if (!empty($variables['header'])) {
     $ts = tablesort_init($variables['header']);
 
@@ -1263,11 +1247,18 @@
       $responsive_index++;
 
       if (!is_array($cell)) {
+        $header_columns++;
         $cell_content = $cell;
         $cell_attributes = new Attribute();
         $is_header = TRUE;
       }
       else {
+        if (isset($cell['colspan'])) {
+          $header_columns += $cell['colspan'];
+        }
+        else {
+          $header_columns++;
+        }
         $cell_content = '';
         if (isset($cell['data'])) {
           $cell_content = $cell['data'];
@@ -1305,6 +1296,7 @@
       $variables['header'][$col_key]['content'] = $cell_content;
     }
   }
+  $variables['header_columns'] = $header_columns;
 
   // Rows and footer have the same structure.
   $sections = array('rows' , 'footer');
diff -u b/core/modules/system/templates/table.html.twig b/core/modules/system/templates/table.html.twig
--- b/core/modules/system/templates/table.html.twig
+++ b/core/modules/system/templates/table.html.twig
@@ -28,12 +28,13 @@
  *     - attributes: Any HTML attributes, such as "colspan", to apply to the
  *       table cell.
  *     - content: The string to display in the table cell.
- *     - active_table_sort: A boolean indicating whether the table sort is
- *       active on cell.
+ *     - active_table_sort: A boolean indicating whether the cell is the active
+         table sort.
  * - footer: Table footer rows, in the same format as the rows variable.
  * - empty: The message to display in an extra row if table does not have
  *   any rows.
  * - no_striping: A boolean indicating that the row should receive no striping.
+ * - header_columns: The number of columns in the header.
  *
  * @see template_preprocess_table()
  *
@@ -83,22 +84,20 @@
           ]
         %}
         <tr{{ row.attributes.addClass(row_classes) }}>
-          {% if empty %}
-            {%
-              set empty_classes = [
-                'empty',
-                'message',
-              ]
-            %}
-          {% endif %}
           {% for cell in row.cells %}
-            <{{ cell.tag }}{{ cell.attributes.addClass(empty_classes) }}>
+            <{{ cell.tag }}{{ cell.attributes }}>
               {{- cell.content -}}
             </{{ cell.tag }}>
           {% endfor %}
         </tr>
       {% endfor %}
     </tbody>
+  {% elseif empty %}
+    <tbody>
+      <tr class="odd">
+        <td colspan="{{ header_columns }}" class="empty message">{{ empty }}</td>
+      </tr>
+    </tbody>
   {% endif %}
   {% if footer %}
     <tfoot>