Может, что-то вроде этого?
<!DOCTYPE html>
<html>
<head>
  <title>Untitled</title>
  <meta charset="utf-8">
  <style type="text/css">
  </style>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.min.js"></script>
</head>
<body>
<div id="app">
   <ul>
            <li v-for="el in ar">
                {{ stringValues(el) }}
            </li>
   </ul>
</div>
  <script>
var arrTest = [{events_id: "1", events_client_id: "1123", events_title: "123", events_description: null, events_worker_id: null},{events_id: "2", events_client_id: "2", events_title: "123", events_description: null, events_worker_id: null}];
const app = new Vue({
  el: "#app",
  data: {
    ar: arrTest
  }
});
function stringValues(obj) {
 var str = "";
  for (key in obj) {
     str += " " + obj[key];
  }
  return str;
}
  </script>
</body>
</html>