You were appending a second table to the first.
Solution: Use <cfsavecontent> and write your content
into the Excel file.
<cfprocessingDirective pageencoding="utf-8">
<cfset setEncoding("form","utf-8")>
<cfquery name="GetScreen_Login" dataSource="VOCTEST">
select STR_EN, STR_FXK FROM VC_SCREEN_STR where STR_SECTION =
'LOGIN'
</cfquery>
<!--- Create table --->
<cfsavecontent variable="myExcelTable">
<table border="1" cellpadding="0" cellspacing="0">
<tr valign="top">
<td><b>Eng</b></td>
<td><b>Kor</b></td>
</tr>
<cfoutput query="GetScreen_Login">
<tr valign="top">
<td>#STR_EN#</td>
<td>#STR_FXK#</td>
</tr>
</cfoutput>
</table>
</cfsavecontent>
<!--- Write table to Excel File --->
<cffile action="write"
file="D:\CustomerVoice\Test_Excel.xls" addnewline="no" charset =
"utf-16" output="#myExcelTable#" />