I've wanted something like this for data entry for a while now. I often find my hands full measuring things and need to take notes. Can this output/format tabular data?
I was then able to go through my list very quickly and add times to each item.
The one failure I had was when I asked it to add whitespace to visually align the table columns.
The table was, however, converted back into a list when I asked it to turn the text into an email.
It's not exactly punching numbers into a spreadsheet, but it worked pretty well for the simple use case I tried.
That said, I would still think it's very doable to set reserved keywords to navigate it ourselves while keeping it conversational.