Excel Merge, whose very large complete name is much more specific: Excel Join (Merge, Combine) Multiple Cells Into One Software, is very useful. It is a plug-in to add to MS Excel that lets you expand multiple rows into just one row, or multiple columns into just one column.
To make this grouping more legible in just one row or column, Excel Merge lets you add separators, like commas, spaces or stops and commas, among the distinct data.
For Excel Merge to work correctly you need MS Excel 2000 or later installed in your PC.