$result .= "<table border='1'>";
    $result .="<tr><td>Cater</td><td>Part</td><td>Gids</td></tr>";
    while ($row = mysql_fetch_array($sql)){
        $result .= '<tr>';
        $result .= '<td>'.$row['Name'].'</td>';
        $result .= '<td>'.$row['Part'].'</td>';
        $result .= '<td>'.$row['Gid'].'</td>';
        $result .= '</tr>';
    }
    $result .= "</table>";
    $result .= "<table border='1'>";
    $result .="<tr><td>Cater</td><td>Dish</td><td>Gids</td></tr>";
    while ($row = mysql_fetch_array($sql)){
        $result .= '<tr>';
        $result .= '<td>'.$row['Name'].'</td>';
        $result .= '<td>'.$row['Dish'].'</td>';
        $result .= '<td>'.$row['Gid'].'</td>';
        $result .= '</tr>';
    }
    $result .= "</table>";

Select
    0 as resultset,
    Name,
    Part,
    Gid
From
    Parts
Union All
    1,
    Name,
    Dish,
    Gid
From
    Dishes
Order By
    resultset -- I'm not sure if you need this, or whether you get it for free

$result .= "<table border='1'>";
$result .="<tr><td>Cater</td><td>Part</td><td>Gids</td></tr>";
while ($row = mysql_fetch_assoc($sql) && $row['resultset'] === 0) {
    $result .= '<tr>';
    $result .= '<td>'.$row['Name'].'</td>';
    $result .= '<td>'.$row['Part'].'</td>';
    $result .= '<td>'.$row['Gid'].'</td>';
    $result .= '</tr>';
}
$result .= "</table>";
$result .= "<table border='1'>";
$result .="<tr><td>Cater</td><td>Dish</td><td>Gids</td></tr>";
while ($row){
    $result .= '<tr>';
    $result .= '<td>'.$row['Name'].'</td>';
    $result .= '<td>'.$row['Part'].'</td>';
    $result .= '<td>'.$row['Gid'].'</td>';
    $result .= '</tr>';
    $row = mysql_fetch_assoc($sql);
}
$result .= "</table>";

$result .= "<table border='1'>";
$result .="<tr><td>Cater</td><td>Part</td><td>Gids</td></tr>";
while ($row = mysql_fetch_array($sql)){
    $result .= '<tr>';
    $result .= '<td>'.$row['Name'].'</td>';
    $result .= '<td>'.$row['Part'].'</td>';
    $result .= '<td>'.$row['Gid'].'</td>';
    $result .= '</tr>';
}
$result .= "</table>";

$result .= "<hr />";         <=========

$result .= "<table border='1'>";
$result .="<tr><td>Cater</td><td>Dish</td><td>Gids</td></tr>";
while ($row = mysql_fetch_array($sql)){
    $result .= '<tr>';
    $result .= '<td>'.$row['Name'].'</td>';
    $result .= '<td>'.$row['Dish'].'</td>';
    $result .= '<td>'.$row['Gid'].'</td>';
    $result .= '</tr>';
}
$result .= "</table>";