If you did not find examples of transforming XML to HTML with XSLT, then you didn't look very hard. That's one of its primary motivations. Anyway, this should get you started:
<?xml version="1.0" encoding="utf-8"?>
<xsl:transform version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:template match="node()|@*"/>
<xsl:template match="/Services">
<html>
<head>
<title>XSLT example</title>
</head>
<body>
<xsl:apply-templates/>
</body>
</html>
</xsl:template>
<xsl:template match="Service">
<xsl:apply-templates/>
</xsl:template>
<xsl:template match="Operations">
<table>
<thead>
<tr>
<td>Name</td>
<td>Description</td>
<td>Type</td>
</tr>
</thead>
<tbody>
<xsl:apply-templates/>
</tbody>
</table>
</xsl:template>
<xsl:template match="Operaion"> <!-- [sic] -->
<xsl:variable name="service" select="ancestor::Service"/>
<tr>
<td><xsl:value-of select="$service/Name"/></td>
<td><xsl:value-of select="Name"/></td>
<td><xsl:value-of select="$service/Category"/></td>
</tr>
</xsl:template>
</xsl:transform>
Output on your (corrected) document (it was missing end tags):
<html>
<head>
<title>XSLT example</title>
</head>
<body>
<table>
<thead>
<tr>
<td>Name</td>
<td>Description</td>
<td>Type</td>
</tr>
</thead>
<tbody>
<tr>
<td>ServiceName</td>
<td>HelloWorld</td>
<td>CatName</td>
</tr>
<tr>
<td>ServiceName</td>
<td>OP2name</td>
<td>CatName</td>
</tr>
<tr>
<td>ServiceName</td>
<td>Op3Name</td>
<td>CatName</td>
</tr>
</tbody>
</table>
</body>
</html>
与恶龙缠斗过久,自身亦成为恶龙；凝视深渊过久,深渊将回以凝视…
