[edoloughlin]

I was thinking more like 200M rows and 16M columns

I don't think a user would be able to meaningfully navigate a table like that by scrolling it. How would they cognitively track where they are or how to return to interesting parts of the data? IMHO, you should rethink how to display and navigate this data. The user would need sophisticated search/filtering support.

[rch]

It's the same as zooming in and out in a google map - if you zoom out, the server is providing e.g. averaged data. Thinking about trackpad navigation around a map of tiles (sections of a spreadsheet) is probably more relevant than scrolling per se.

A side window let's you navigate at a high level (low res) and zoom in to data-dense areas. Low level / high res navigation in the grid might be used for exploring data from individual sensors, in context with interpolated values.

You can keep the scrollbars from becoming irrelevant by scaling to the size of a logical grid 'neighborhood' of adjacent tiles at the current zoom level.