merge
Merges the range cells into a single merged cell. If the range already includes a merged cell, they are merged, too.
Example
<div id="spreadsheet"></div>
<script type="text/javascript" charset="utf-8">
$("#spreadsheet").kendoSpreadsheet();
var spreadsheet = $("#spreadsheet").data("kendoSpreadsheet");
var sheet = spreadsheet.activeSheet();
sheet.range("A1:B2").merge();
</script>