<?php
$tabacos1 = $tabacos->fetchAll();
while ($item2 = $listado->fetch()) {
    ?>

            <tr>
                <td>Carril nº: <?php echo $item2['idCarrilTabaco'] ?></td>

                <td>
                    <select name="descripcion" size ="1">
                    <?php foreach ($tabacos1 as $tabacos2) {?>
                            <option value='<?php echo $tabacos2['idTabaco']?>'><?php echo $tabacos2['descripcion']?></option>
                   <?php } ?>
                    </select>


                </td>


                <td><?php echo $item2['Capacidad'] ?></td>
                <td><input type = "text" name = "cantidad" size ="2" value="<?php echo $item2['Cantidad'] ?>"></td>

            </tr>

    <?php
}
?>