Recover Json after success and use in PHP

I have the javascript code that returns me in a variable 'msg' the result of a query made in PHP.

  var page = "busca.php";
    $.ajax({
        type: 'POST',
        dataType: 'html',
        url: page,

        data: {idtabela: idtabela},
        success: function (msg) {
            //preciso transferir os dados no formato json par ao php
            msg = $.parseJSON(msg);              
        }
    });

This data is json format, I need to transfer it to another php file. To be more precise, I'm using the DataTables plugin. In it I already loop a sql query in the database. Now I need to give the user the option on which table he wants to query, thus changing the query with each click. I thought of doing in the file where the table is, a variable that receives the json and throw in the DataTables