まず、CSVにデータがある

このデータを元に連想配列を作る
$data = [];
$fp = fopen("Book.csv", "r");
while(! feof($fp)){
$csv = fgets($fp);
$csv = trim($csv,'"');
$csv = mb_convert_encoding($csv, "UTF-8", "utf-8");
$csv = str_replace('"','',$csv);
$array = explode(",",$csv);
$data[$array[0]] = $array[1];
}
echo "<pre>";
var_dump($data);
echo "</pre>";

まあOKっぽい。。