PHP foreach行为2列

I need to generate PDF page based on PHP foreach result and display 2 columns (A4 PDF Landscape mode). For e.g. Data look like this:

Row data 1
Row data 2
Row data 3
Row data 4
Row data 5
Row data 6

if the height exceeds in PDF column 1 (HTML table), it will move to 2nd column of page and it looks like:

    Row data 1  Row data 7
    Row data 2  Row data 8
    Row data 3  Row data 9
    Row data 4
    Row data 5
    Row data 6

My code:

<table  width="100%"  cellspacing="0" cellpadding="0"  border="0">
    <thead>
        <tr>
           <th width="140px">Subject</th>
           <th width="100px">Teacher</th>
           <th width="8%">Exam</th>
        </tr>
    </thead>
<tbody>
<?php 
    foreach($data as $std)
    {
?>
<tr>
    <td><?php echo $std->data1; ?></td>
    <td><?php echo $std->data2; ?></td>
    <td><?php echo $std->data3; ?></td>
</tr>
<?php
}
?>
</tbody>
</table>

try like this

require('fpdf.php');//download fpdf and include
$pdf = new FPDF();
 $myarray = array(1,2,3);
$pdf->SetFont('Arial','B',16);  
foreach($myarray as $value){
$pdf->AddPage();
$pdf->Cell(40,10,$value);
}
$pdf->Output()

A4 is actually height:297mm and width:210mm for web in Portrait follow this link for more http://www.thecalculatorsite.com/forum/topics/width-and-height-a4-paper.php. So for landscape it will be height:210mm and width:297mm. I have given you an approximate code for your purpose. Modify the $max_rows with how many rows a page can contain without breaking. And style the height width property of the table, columns and rows to support your need.

<!DOCTYPE html>
<html>
    <head>
        <style>
        body {
            height: 210mm;
            width: 297mm;
            /* to centre page on screen*/
            margin-left: auto;
            margin-right: auto;
        }
        </style>
    </head>
    <body>
    <table  style="float:left;" width="50%" cellspacing="0" cellpadding="0"  border="0">
        <thead>
            <tr>
                <th width="140px">Subject</th>
                <th width="100px">Teacher</th>
                <th width="8%">Exam</th>
            </tr>
        </thead>
        <tbody>
    <?php
    $max_rows = 6;
    $count_row = 0;
    foreach($data as $std)
    {
        $count_row++;
        if($count_row > $max_rows)
            $count_row = 0;

        if($count_row == 0) {
    ?>
        </tbody>
    </table>

    <table  style="float:left;" width="50%" cellspacing="0" cellpadding="0"  border="0">
        <thead>
            <tr>
                <th width="140px">Subject</th>
                <th width="100px">Teacher</th>
                <th width="8%">Exam</th>
            </tr>
        </thead>
        <tbody>
<?php } ?>
            <tr>
                <td><?php echo $std->data1; ?></td>
                <td><?php echo $std->data2; ?></td>
                <td><?php echo $std->data3; ?></td>
            </tr>
<?php
}
?>
        </tbody>
    </table>
    </body>
</html>