This job iterates over groovy-defined collection of sheets, queries all of them with excel driver and writes a JOB_LOG entry.

<!DOCTYPE etl SYSTEM "https://scriptella.org/dtd/etl.dtd">
<etl>
<description>Import multiple excel sheets</description>
 
<properties>
file=C:/Data/data.xlsx
</properties>
 
<connection id="groovy" driver="script">language=groovy</connection>
 
<connection id="logger" driver="log">
level=WARN
</connection>
 
<connection id="excel" driver="excel">
format=XLSX
</connection>
 
<!-- Define multiple sheets -->
<!-- And iterate over them -->
<!-- Note: query.next() have to be called in order to move to nested queries -->
<query connection-id="groovy">
<![CDATA[
 
def sheets = ["Sheet1","Sheet2","Sheet3"]
 
for(sheet in sheets) {
etl.globals['sheet'] = sheet
query.next()
}
]]>
 
<query connection-id="excel">
path=$file
sheet=${etl.globals['sheet']}
skip_rows=1
num_columns=15
escapeChars='"
 
<script connection-id="logger">
Imported: $row.A, $row.B
</script>
 
</query>
 
</query>
 
</etl>