This appears to be possible, but not with any OOTB nodes (or user-created packages either, as far as I am aware). Here is an explanation of how to group rows in an Excel worksheet using the Excel Interop. This would require writing a custom Python node, adding a reference to the Excel Interop. Here is an example I have made previously, largely borrowing from another example in the IronPython Cookbook.
TL;DR: Possible, but requires coding knowledge.