fixed

--code.gs

    function createArtistTable(name)
    {
        var message = "test";

        var obj = {message: message, name: name};
    	return obj;
    }

--js.html

    function openArtistTable(name)
    {
        google.script.run
            .withSuccessHandler(openSuccess)
            .withFailureHandler(openFailure)
            .createArtistTable(name)
    }

    function openSuccess(object)
    {
    	var x = object.message;
		var y = object.name;
    	console.log(x);
    	console.log(y);
    }