>> I don't want to use jQuery
sorry dude, once you use sapui5 you start using jquery ;-)
iwould ercommend some changes
oData[y]["value_"+x] = "";
....
var oModel = new sap.ui.model.json.JSONModel( oData );
oTableau.setModel(oModel, "test");
value:"{test>value_0}",
...
value:"{test>value_1}",
...
value:"{test>value_2}",