En gros :
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes"/>
<xsl:template match="/NewDataset">
<Workbook>
<xsl:for-each select="*[starts-with(name(), 'Table')]">
<Worksheet>
<xsl:for-each select="record">
<Row>
<xsl:for-each select="*">
<Cell>
<xsl:value-of select="." />
</Cell>
</xsl:for-each>
</Row>
</xsl:for-each>
</Worksheet>
</xsl:for-each>
</Workbook>
</xsl:template>
</xsl:stylesheet>