The ‘Personal Finance’ templates when creating a new spreadsheet give an idea of this: you can have multiple tables each with different dimensions, headers, summary rows, etc. You can also have charts, graphics, and text boxes with fairly advanced layout.
It would take too long to anonymise some of my specific examples, but I use this extensively in my financial and tax spreadsheets. I know you can bodge multiple tables on one sheet in Excel, but it’s not a good idea because it quickly makes equations overly complex or error-prone. For instance, you can’t do =SUM(C)
if your column C includes multiple different conceptual tables. Having multiple, distinct, tables all displayed on the same sheet that can be configured for their specific purpose and reference each other is a game changer.
Wikipedia also has a pretty good description of the different conceptual model Numbers uses:
Numbers works in a fashion somewhat different from traditional spreadsheets like Microsoft Excel or Lotus 1-2-3. In the traditional model, the table is the first-class citizen of the system, acting as both the primary interface for work and as the container for other types of media like charts or digital images. In effect, the spreadsheet and the table are the same. In contrast, Numbers uses a separate “canvas” as its basic container object and tables are among the many objects that can be placed within the canvas.
[…]
[In Excel] sheets often grow very complex with input data, intermediate values from formulas, and output areas, separated by blank areas. To manage this complexity, Excel allows one to hide data that is not of interest, often intermediate values. […]
In contrast, Numbers does not have an underlying spreadsheet in the traditional sense but uses multiple individual tables for this purpose. Tables are an X and Y collection of cells, like a sheet, but extend only to the limits of the data they hold. Each section of data or output from formulas can be combined into an existing table or placed into a new table. Tables can be collected by the user onto single or multiple canvases. Whereas a typical Excel sheet has data strewn across it, a Numbers canvas could build the same output through smaller individual tables encompassing the same data.
Numbers (spreadsheet) - Wikipedia
Edit: Looks like Lotus attempted to rethink how a spreadsheet could work in the 1990s. Kind of amazing that except for Numbers (which is less ‘ambitious’ in rethinking the underlying model than Lotus Improv was) there’s not been any mainstream attempt to rethink how a spreadsheet could work since VisiCalc created the spreadsheet in the 1970s.