What i wanted to do is access random property for example let1, let2 with their first string in array which is ID "1" , "2" , "3" , "4" , "5". brojleta is actually that ID i mentioned before, it is different from id down there(var id = item[0][1]). What i need is to get all other strings based on their ID. I tried it like this :
var data = {
    let1:[["1","2","10.2.2019.","11.2.2019.","Beograd Aerodrom","Amsterdam Aerodrom","30","12000"]],
    let2:[["2","4","15.2.2019.","16.2.2019","Amsterdam Aerodrom","Rim Aerodrom","30","8000"]],
    let3:[["3","6","25.2.2019.","28.2.2019.","Rim Aerodrom","Beograd Aerodrom","30","8000"]],
    let4:[["4","8","13.2.2019.","14.2.2019.","Beograd Aerodrom","Moskva Aerodrom","30","13000"]],
    let5:[["5","10","1.3.2019.","4.3.2019.","Beograd Aerodrom","New York Aerodrom","30","18000"]]
};
function getParamValue(brojleta) {
  var location = decodeURI(window.location.toString());
  var index = location.indexOf("?") + 1;
  var subs = location.substring(index, location.length);
  var splitted = subs.split("&");
  for (i = 0; i < splitted.length; i++) {
    var s = splitted[i].split("=");
    var pName = s[0];
    var pValue = s[1];
    if (pName == brojleta) {
      return pValue;
    }
  }
}
var brojleta = getParamValue("id");
var item = data.find(item => item[0][0] === brojleta);
var id = item[0][1]
var datumpolaska = item[0][2]
var datumdolaska = item[0][3]
var polazniaerodrom = item[0][4]
var dolazniaerodrom = item[0][5]
var brojsedista = item[0][6]
var cenakarte = item[0][7]
  var data1 = data.let1[0];
  var data2 = data.let2[0];
  var data3 = data.let3[0];
  var data4 = data.let4[0];
  var data5 = data.let5[0];
  
  /* this is the code for adding data from array to table */
  
  $(document).ready(function(){
    var row1cells = $("#row1 td");
    var row2cells = $("#row2 td");
    var row3cells = $("#row3 td");
    var row4cells = $("#row4 td");
    var row5cells = $("#row5 td");
  
    for (var index=0; index<8; index++) {
      $(row1cells[index]).html(data1[index]);
      $(row2cells[index]).html(data2[index]);
      $(row3cells[index]).html(data3[index]);
      $(row4cells[index]).html(data4[index]);
      $(row5cells[index]).html(data5[index]);
    }
  }); 
     
     
     
    