@Sironi 

As mentioned by Pradeep you need to query the table and get the value

Sample script below which is updated

Ensure you give valid table names, list variable name , field names, etc

template.print("<b>Summary of Requested items:\n</b>");
var item = new GlideRecord("sc_req_item");
if (item.get(current.document_id)) {
template.print("<b>"+item.number + ": " + item.cat_item.getDisplayValue() + "</b><br/>");
var keys = new Array();
var set = new GlideappVariablePoolQuestionSet();
set.setRequestID(item.sys_id);
set.load();
var vs = set.getFlatQuestions();
for (var i = 0; i < vs.size(); i++) {
if (vs.get(i).getDisplayValue() != '' && vs.get(i).getName() != 'listVariableName') {
template.print("<b>"+vs.get(i).getLabel() +"</b>"+ " : " + vs.get(i).getDisplayValue() + "<br/>");
}

if(vs.get(i).getName() == 'listVariableName'){

var gr = new GlideRecord('table name'); // give table name being referred by list variable

gr.addQuery('sys_id', 'IN', item.variables.<listVariable>);

gr.query();

while(gr.next()){

template.print('Owner is' + gr.<ownerField> + '<br/>');

}

}
}
}

Regards
Ankur