/* @group Attachments table */
table.attachments caption {
  display: none;
}
table.attachments {
  border-color: #CCC;
  border-width: 1px;
  border-style: solid none none solid;
  width: auto;
}
table.attachments thead { border: 1px solid #CCC }
table.attachments td {
  line-height: 24px; padding: 0;
  border-right: 1px solid #CCC;
  border-bottom: 1px solid #CCC;
}
table.attachments tr {
  border-right: 1px solid #CCC;
}
table.attachments td a {
	line-height: 24px;
	padding: 0 26px;
	background-position: 5px;
	background-repeat: no-repeat;
}
table.attachments th {
  background-color: #F2F2F2;
  font-weight: normal;
  font-family: Arial, Helvetica, "Lucida Grande", "Lucida Sans Unicode", Verdana, sans-serif;
  font-size: 77%;
}
table.attachments td.size {
  padding: 0 5px;
  font-family: Arial, Helvetica, "Lucida Grande", "Lucida Sans Unicode", Verdana, sans-serif;
  font-size: 77%;
  color: #404040;
  font-style: normal;
}
/* @end */
/* @group Mime-type icons */
.pdf a, .application-pdf a {
  background-image: url(images/icon-pdf.gif); }
.jpeg a, .jpg a, .png a, .gif a {
  background-image: url(images/icon-image.png); }
.eps a, .application-postscript a {
  background-image: url(images/icon-postscript.png); }
.html a, .text-html a {
  background-image: url(images/icon-html.gif); }
.qt a, .video-quicktime a {
  background-image: url(images/icon-quicktime.gif); }
.ical a, .text-calendar a {
  background-image: url(images/icon-ical.gif); }
.dl a {
  background-image: url(images/icon-download.gif); }
.dmg a, .application-x-diskcopy a {
  background-image: url(images/icon-dmg.gif); }
.zip a, .application-zip a {
  background-image: url(images/icon-zip.gif); }
.audio a, .audio-mpeg a {
  background-image: url(images/icon-audio.gif); }
.website a {
  background: url(images/icon-website.gif) left center no-repeat;
  margin: 0; padding: 2px 0 2px 25px; line-height: 25px; }
.doc a, .msword a {
  background-image: url(images/icon-doc.png); }
.txt a  {
  background-image: url(images/icon-txt.gif); }
/* @end */

/**
 * Attachments
 *******************************************************/
 
table.attachments caption {
  display: none;
}
table.attachments {
  border-color: #CCC;
  border-width: 1px;
  border-style: solid none none solid;
  width: auto;
}
table.attachments thead { border: 1px solid #CCC }
table.attachments td {
  line-height: 24px; padding: 0;
  border-right: 1px solid #CCC;
  border-bottom: 1px solid #CCC;
}
table.attachments tr {
  border-right: 1px solid #CCC;
}
table.attachments td a {
	line-height: 24px;
	padding: 0 26px;
	background-position: 5px;
	background-repeat: no-repeat;
}
table.attachments th {
  background-color: #F2F2F2;
  font-weight: normal;
  font-family: Arial, Helvetica, "Lucida Grande", "Lucida Sans Unicode", Verdana, sans-serif;
  font-size: 77%;
}
table.attachments td.size {
  padding: 0 5px;
  font-family: Arial, Helvetica, "Lucida Grande", "Lucida Sans Unicode", Verdana, sans-serif;
  font-size: 77%;
  color: #404040;
  font-style: normal;
}

/**
 * Mime-type icons
 *******************************************************/
.pdf a, .application-pdf a {
  background-image: url(/sites/all/misc/images/icon-pdf.gif); }
.jpeg a, .jpg a, .png a, .gif a {
  background-image: url(/sites/all/misc/images/icon-image.png); }
.eps a, .application-postscript a {
  background-image: url(/sites/all/misc/images/icon-postscript.png); }
.html a, .text-html a {
  background-image: url(/sites/all/misc/images/icon-html.gif); }
.qt a, .video-quicktime a {
  background-image: url(/sites/all/misc/images/icon-quicktime.gif); }
.ical a, .text-calendar a {
  background-image: url(/sites/all/misc/images/icon-ical.gif); }
.dl a {
  background-image: url(/sites/all/misc/images/icon-download.gif); }
.dmg a, .application-x-diskcopy a {
  background-image: url(/sites/all/misc/images/icon-dmg.gif); }
.zip a, .application-zip a {
  background-image: url(/sites/all/misc/images/icon-zip.gif); }
.audio a, .audio-mpeg a {
  background-image: url(/sites/all/misc/images/icon-audio.gif); }
.website a {
  background: url(/sites/all/misc/images/icon-website.gif) left center no-repeat;
  margin: 0; padding: 2px 0 2px 25px; line-height: 25px; }
.doc a, .msword a {
  background-image: url(/sites/all/misc/images/icon-doc.png); }
.txt a  {
  background-image: url(/sites/all/misc/images/icon-txt.gif); }

The following styles are designed to work with the markup from a custom theme override template called [upload_attachments.tpl.php](http://snipplr.com/view/11851)

Drupal custom styles for upload attachments table

css, drupal, theme

CSS