Алексей Колесников

div { width:90px; height:90px;
	position:fixed; z-index:2; left:0; top:0;
	-webkit-animation-name: 'anime';
	-webkit-animation-duration: 1000ms;
	-webkit-animation-iteration-count: infinite;
	-webkit-animation-direction: normal;
	-webkit-animation-timing-function: linear;
	animation-name: 'anime';
animation-duration: 1000ms;
animation-iteration-count: infinite;
animation-direction: normal;
animation-timing-function: linear;
	background:#1E800E;}
@-webkit-keyframes 'anime' {
	from {left:0}
	50% {left:60px}
	60% {left:50px}
        70% {left:60px;}
	to {left:0px}
}

<div id="main">
    <table>
      <thead>
        <tr>
          <td><div class="but">Действие 1<ul><li>1</li><li>2</li><li>3</li></ul></div></td>
          <td><div class="but">Действие 2<ul><li>1</li><li>2</li><li>3</li></ul></div></td>
          <td><div class="but">Действие 3<ul><li>1</li><li>2</li><li>3</li></ul></div></td>
        </tr>
      </thead>
    </table>
  </div>

table td { padding:10px 50px; background-color: green; color:white;}
  table a {color:white; text-decoration:none;}
.but {display:block; cursor:pointer; position: relative;}
.but ul {display:none;}
.but:hover ul {display:block; position:absolute; left:0; top:100%; padding:0; margin:0; list-style:none;z-index:2; width:100%; background:#ccc;}
.but ul li {display:block; padding:5px; color:#000;}
.but ul li:hover {color:#FFF; background:#666}