OK, I am getting the picture. Let's make it step by step. Below is the code to display a form with three checkboxes and a submit button. If the form gets submited the script will read the events from selected tables and display those events. You can adapt this code to suit your requirements. Please note that I have changed the names of tables from table to calendar to make things clear and to avoid possible mistakes (I think it is not a good idea to use general terms or reserved words for variable names). See explanations in comments.
<?php
// if form was submitted and if array with calendar names exists and is not empty
if(isset($_POST['calendar']) && !empty($_POST['calendar']))
{
// connect to the database
$con = mysql_connect("","","");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
mysql_select_db("", $con);
// process selected tables (calendars)
// - read events from each calendar
// - display events for that calendar
foreach($_POST['calendar'] as $calendar)
{
// query to read events from one calendar
$q_select = "SELECT * FROM $calendar ";
$result = mysql_query($q_select);
// display calendar name
echo "<h3>$calendar</h3>";
// list of events (i.e from three columns, separated with a <br />
// but you could display this in a html table)
while($row = mysql_fetch_row($result))
{
echo "<p>{$row[0]}<br />{$row[1]}<br />{$row[2]}</p>";
}
}
}
?>
<form method="post" action="#">
<input type="checkbox" name="calendar[]" value="calendar_A" checked="checked"/>Calendar A<br />
<input type="checkbox" name="calendar[]" value="calendar_B"/>Calendar B<br />
<input type="checkbox" name="calendar[]" value="calendar_C"/>Calendar C<br />
<input type="submit" name="submit" value="Submit">
</form>
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