Excel's new ability to nest arrays and other compound data inside cards is not a minor feature addition, it's a direct challenge to the assumption that spreadsheets must flatten complexity into rows and columns. The Reddit user behind this discovery, u/SetBee, demonstrates something genuinely useful: by using the `valuesAsJson` method, you can embed an entire array of doubles inside a single cell, and even nest an entity inside that array. This means a single cell can now carry structured, hierarchical data that previously required multiple helper columns, pivot tables, or external scripts. For anyone who has wrestled with Power Query returning "[List]" or "[Record]" as unhelpful text strings, this is a practical path forward.
The practical payoff is immediate. Instead of converting a nested list into text like "{1,2,3}" and then parsing it with EVALUATE or TEXTSPLIT, workarounds that u/SetBee rightly calls "not optimal", you can now store and retrieve that structure directly. The card system supports three types of rich data: linked entities (stocks, currencies), entities from Power Query, and basic types. Basic types behave predictably in functions, meaning their metadata doesn't interfere with calculations. That's critical: it means you can embed an array inside a card, use that cell in a formula, and have the formula see the card's basic value, not the nested complexity. The data stays rich for exploration, but lean for computation.
What's missing, and what u/SetBee highlights, is that this power isn't yet accessible from Power Query or Office Script. The `valuesAsJson` method works in the Excel JavaScript API, but not in Office Script or VBA. And while Microsoft's documentation lists a "function" cell value type, attempts to nest a function inside a card have failed. The potential is clear: if worksheet functions could create these cards directly, imagine a `MAKEENTITY` or `SETPROPERTY` function, then users could build rich data structures without writing a line of code. Until that happens, the workaround is the API, which is a step forward, but not yet a leap.
Our view is straightforward: this capability deserves to be pulled out of the API and into the worksheet. The technology is already there. The infrastructure for cards and nested arrays is proven in the JavaScript API. What's needed is a user-facing function that lets anyone, not just those comfortable with Script Lab, create and manipulate these structures. u/SetBee's experiments show that the foundation is solid. Now it's time to build the bridge.