No you cannot do that, however you could plug the values of * into an array and loop through each table, stacking an array with the values you want.
$array = (table1,table2,table3);
$cArray = array();
for($i=0;$i<count($array);$i++)
{
$sql = mysql_query("SELECT * FROM forum_".$array[$i]."_config ");
while($row = mysql_fetch_array($sql))
{
array_push($cArray,$row[value]);
}
}