<?php
$mysqli = new mysqli("localhost","root","","your_db",3306);

// Our table
// CREATE TABLE names(id int,first_name varchar(45),last_name varchar(45));

$qry=<<<QUERY
INSERT INTO 
names(id,first_name,last_name)
VALUES
    (1,"Thomas","Shelby"),
    (2,"Joe","McMillan"),
    (3,"Bruce","Robertson")
QUERY;

// That's it ...You inserted multiple records at once
$mysqli->query($qry);

// Let's check
$qry="SELECT * FROM names";
$result = $mysqli->query($qry);

while ($row = $result->fetch_assoc()) {
    print_r($row);
}

?>