Basically, Excel Easy
Table.vi in Report Generation Toolkit has auto format option which allows you to choose table type that is applied for your data.
If you want to just insert data into your Excel file, you can implement the functionality by following manner. In the image below, using Report Generation Toolkit is assumed.
Input row and column information into Row Col To Range
Format.vi and wire output of this function into
Range.

Row Col To Range
Format.vi is placed in the following path (the function name can be IM_Row_Col_To_Range_Format.vi)
C:\Program Files (x86)\National Instruments\<LabVIEW version>\vi.lib\imath\common
If you want to insert multiple data like Table format but still you do not want any ruled line to be included, you can modify the code something like below.
Note that above-mentioned code is implemented as sub vi called excel_single_cell_write.vi.