Yes, you're right! In practice, though, we're finding that many useful customizations can fit into that framework. For example, the Expedia demo in the paper sh

Yes, you're right! In practice, though, we're finding that many useful customizations can fit into that framework. For example, the Expedia demo in the paper shows a "1 row table" to represent an input form. It's worth thinking about how many different things people use spreadsheets for... I think another useful analogy for thinking about abstract data representations is text streams in UNIX. It turns out many types of data can be represented as newline-delimited text, which enables you to use a suite of generic tools with that data. Inevitably, some data doesn't fit into that format, but it's perhaps surprising how much does.