You have to mention table columns , width , height as in different places default values are different
$PHPWord = new PHPWord();
// document style orientation and margin
$sectionStyle = array('orientation' => 'landscape', 'marginLeft'=>600, 'marginRight'=>600, 'marginTop'=>600, 'marginBottom'=>600, 'colsNum' => 2);
$section = $PHPWord->createSection($sectionStyle);
// Define table style arrays
$styleTable = array('borderSize'=>6, 'borderColor'=>'006699', 'cellMargin'=>80, 'width'=>100);
// Define font style for first row
$fontStyle = array('bold'=>true, 'align'=>'center');
// Add table style
$PHPWord->addTableStyle('myOwnTableStyle', $styleTable);
// Add table
$table = $section->addTable('myOwnTableStyle');