.r3-wrap{ position:relative; display:inline-block; width:100%; }

table.r3 {
  width:100%;
  border-collapse: collapse;
  text-align: center;
  margin: 0px 0px 7px 0px;
  box-sizing: border-box;
}

.r3 td {
  border: 1px solid #ccc;
  padding: 6px 10px;
}

.r3-arrow{
  position:absolute;
  pointer-events:none;
  transform: translate(-50%, -50%) rotate(45deg);
  transform-origin:center;
  font-size: 55pt;      /* tu ajustes */
  opacity: 1;
  z-index: 5;
  color:#1a5fb4;
}