How to add two columns in the end of table

I want to add two columns like shown in the screenshot 
Code
public report: Object = {
dataSource: {
data:tableData,
mapping: {
Date: [
{
uniqueName:”Week”,
type:”datetime”,
interval:”w”,
format:”d-MMM”
},
{
uniqueName:”Month”,
type:”datetime”,
interval:”M”,
format:”MMM”
},
],
}
},
slice: {
rows: [
{
uniqueName:”Cell”
},
{
uniqueName:”Bucket”
},
],
columns: [
{
uniqueName:”Month”
},
{
uniqueName:”Week”
}
],
measures: [
{
uniqueName:”Price”,
},
 
],
expands: {
expandAll:true
}
},
options: {
grid: {
type:”classic”,
showTotals:”off”,
showFilter:false,
showHeaders:false,
showGrandTotals:”off”,
showAutoCalculationBar:false
},
configuratorButton:false
}
};
Data 
[
{
“Cell”: “CANSTACK”,
“Price”: 697,
“Bucket”:”With < 5% addition”,
“Date”: “2018-02-28”,
“Data”:”123″
},
{
“Cell”: “BLDC”,
“Price”: 1118,
“Bucket”:”Newly Reflecting”,
“Date”: “2018-02-12”,
“Data”:”123″
},
{
“Cell”: “BUDC”,
“Price”: 698,
“Bucket”:”Part added within 4 weeks”,
“Date”: “2018-01-28”,
“Data”:”123″
},
{
“Cell”: “BLDC”,
“Price”: 880,
“Bucket”:”Newly Reflecting”,
“Date”: “2018-01-24”,
“Data”:”123″
},
{
“Cell”: “BLDC”,
“Price”: 938,
“Bucket”:”Newly Reflecting”,
“Date”: “2018-03-28”,
“Data”:”123″
},
{
“Cell”: “CANSTACK”,
“Price”: 966,
“Bucket”:”With < 5% addition”,
“Date”: “2018-02-06”,
“Data”:”123″
},
{
“Cell”: “BLDC”,
“Price”: 780,
“Bucket”:”Newly Reflecting”,
“Date”: “2018-01-19”,
“Data”:”123″
},
{
“Cell”: “CANSTACK”,
“Price”: 491,
“Bucket”:”With < 5% addition”,
“Date”: “2018-01-22”,
“Data”:”123″
},
{
“Cell”: “BUDC”,
“Price”: 327,
“Bucket”:”Part added within 4 weeks”,
“Date”: “2018-02-15”,
“Data”:”123″
},
{
“Cell”: “BUDC”,
“Price”: 938,
“Bucket”:”Part added within 4 weeks”,
“Date”: “2018-01-04”,
“Data”:”123″
},
{
“Cell”: “CANSTACK”,
“Price”: 774,
“Bucket”:”With < 5% addition”,
“Date”: “2018-01-03”,
“Data”:”123″
},
{
“Cell”: “BUDC”,
“Price”: 832,
“Bucket”:”Part added within 4 weeks”,
“Date”: “2018-03-30”,
“Data”:”123″
},
{
“Cell”: “BLDC”,
“Price”: 819,
“Bucket”:”Newly Reflecting”,
“Date”: “2018-02-08”,
“Data”:”123″
},
{
“Cell”: “BUDC”,
“Price”: 964,
“Bucket”:”Part added within 4 weeks”,
“Date”: “2018-03-31”,
“Data”:”123″
},
{
“Cell”: “BUDC”,
“Price”: 323,
“Bucket”:”Part added within 4 weeks”,
“Date”: “2018-03-10”,
“Data”:”123″
}
]