[Dilettante_Pro]

Ну, насчет стиля...

<style>
button { display:none;}
td:hover div { background-color: lightgreen; }
td:hover button { display:block; }
</style>
<table border="1" width="200">
   <tr>
     <td>
         <div contenteditable>div 111</div><div contenteditable>div 112</div>
        <button>Запись</button>
        <button>Отмена</button>
     </td>
     <td>
         <div contenteditable>div 121</div><div contenteditable>div 122</div>
     </td>
   </tr>
   <tr>
     <td>
         <div contenteditable>div 211</div><div contenteditable>div 212</div>
     </td>
     <td>
         <div contenteditable>div 221</div><div contenteditable>div 222</div>
     </td>
   </tr>
</table>