Remove the border="1" attribute but leave the cellspacing. Then go into styles.css and either add your CSS selectors or modify the existing selectors. If your table is within the id="content" block, the styling is being affected by the existing selectors. The ones you will want to adjust are:

 #content table {
 border: 1px solid #e7e7e7;
 margin: 0 -1px 24px 0;
 text-align: left;
 width: 100%;
  }
  #content tr th,
  #content thead th {
   color: #888;
   font-size: 12px;
   font-weight: bold;
   line-height: 18px;
   padding: 9px 24px;
   }
   #content tr td {
    border-top: 1px solid #e7e7e7;
    padding: 6px 24px;
   }
   #content tr.odd td {
    background: #f2f7fc;
   }

Remove the border="1" attribute but leave the cellspacing. Then go into styles.css and either add your CSS selectors or modify the existing selectors. If your table is within the id="content" block, the styling is being affected by the existing selectors. The ones you will want to adjust are:

#content table {
    border: 1px solid #e7e7e7;
    margin: 0 -1px 24px 0;
    text-align: left;
    width: 100%;
}
#content tr th,
#content thead th {
    color: #888;
    font-size: 12px;
    font-weight: bold;
    line-height: 18px;
    padding: 9px 24px;
}
#content tr td {
    border-top: 1px solid #e7e7e7;
    padding: 6px 24px;
}
#content tr.odd td {
    background: #f2f7fc;
}