Interestingly, Apple's Numbers tries to break people of this (perhaps unsuccessfully) by decoupling the 'sheet' with the column/row/cells grids. You can have multiple cell tables on a single page.
When I first saw this functionality I was really excited by it as a way to keep data consistent and independent of the layout. In reality I think the tooling around creating/moving/linking the cell groups is a bit awkward to use. Perhaps some day it will get there, or someone else will pick up the idea and run with it some more.
You miss the point, both Lotus Improv and Excel are an (pseudo-)endless wall of cells.
Numbers puts bounded tables on a page instead of fitting the pages (and everything, really) into an endless table dating from Multiplan, thus solving the "hacking the cells to implement layout" problem. In this example a table is actually selected, and allows for south, east and south-east extension.