$books = [
['ISBN', 'title', 'author', 'publisher', 'ctry' ],
[618260307, 'The Hobbit', 'J. R. R. Tolkien', 'Houghton Mifflin', 'USA'],
[908606664, 'Slinky Malinki', 'Lynley Dodd', 'Mallinson Rendel', 'NZ']
];
$xlsx = SimpleXLSXGen::fromArray( $books );
$xlsx->saveAs('books.xlsx');
// $xlsx->downloadAs('books.xlsx');