I believe this patent has exactly zero chance of succeeding. Let me illustrate why, in depth.
Start with the patent. Recall that a patent's legal force is basically equivalent to its Claims. Those start here:
Read the claims. They fall into two basic groups. The vast majority of the claims cover the existence, visual display and manipulation of a tabbed spreadsheet display. The only claims that do not apply to the tabs themselves are 10 and 11, which refer to how the data in those tabs is referred to in other cells. The long and short is that Quattro patented the idea of having a workbook with multiple sheets.
Numbers does not have tabs. It has sheets, but they are very different than those in Quattro, and you don't refer to them directly. Instead, you can place multiple *tables* anywhere you want - on a sheet, on a canvas, or anywhere you want. Numbers is utterly different than what this patent encodes.
That leaves claims 10 and 11. These deal with the *referencing* of the data, and specifically states you do this with a colon. Numbers uses a double colon. They got it from Excel, which I suspect make this change specifically to bypass this patent.
As if that were not enough, also recall the whole concept of "prior art". There are multiple examples of this system in use prior to Quattro:
Thus the patent can only stand on those parts that are specific to Quattro, as the general concept was already in use. If those portions don't fail due to the obvious test, then they certainly aren't applicable to Numbers, which looks and works in an entirely different fashion.
Good luck, troll.