@Rukmani_Splunk will you Splunk Tables have fixed number of columns?
<row>
<html depends="$alwaysHideCSSStyle$">
<style>
#sample table thead th{
width: 200px !important;
}
</style>
</html>
</row>
<row>
<panel>
<table id="sample">
your table query
please modify width args.