JSFiddle - React, Tailwind, and code Playground

JavaScript

var arr=[
    {
      "columns": [
        {
          "value": "00TK000000INaMXMA1",
          "fieldNameOrPath": "Id"
        },
        {
          "value": "ght",
          "fieldNameOrPath": "Sub"
        },
        {
          "value": "Normal",
          "fieldNameOrPath": "Pri"
        }
      ]
    },{
      "columns": [
        {
          "value": "00TKabc",
          "fieldNameOrPath": "Id"
        },
        {
          "value": "abc",
          "fieldNameOrPath": "Sub"
        },
        {
          "value": "pqr",
          "fieldNameOrPath": "Pri"
        }
      ]
    }];
console.log(arr)
//debugger;
for(var i=0; i<arr.length;i++){
    for (var k=0; k<arr[i].columns.length;k++)
    delete arr[i].columns[0]
}
console.log(arr)