For big data structures, horizontal arrangement is preferable to avoid wasting space between branch text and data lists.
Placing it between two pieces of scripts allows for efficient reference and retrieval of data.
This is an interesting idea we can look into. The closest discussion on this was this style of enhanced panel: Enhanced Panel Request - #3 by AndersDeleuran.
There are spreadsheet components that might do something similiar.
On a different note I created a vibe coded column panel that may or may not work for you:
Drag the GHA into Rhino and you may see a blank icon params utility toolbar that is multi-column panel:
MultiColumnPanel.deps.zip (15.5 KB)
For fun here is a refined version:
Here’s a Horizontal Panel component that does what you’re describing — it wraps a long list into columns instead of one tall list, and in a data tree each branch gets its own column with the path as a header
HorizontalPanel.zip (28.0 KB)
To install: unzip, then right-click HorizontalPanel.gha → Properties → tick Unblock (Windows blocks downloaded plugins and Grasshopper will silently skip it otherwise). Then drag the .gha onto an open Rhino window, or copy it to %APPDATA%\Grasshopper\Libraries, and restart Rhino. It appears in Params → Util.
Right-click the panel for Show Paths, Show Indices, Max Column Width, Font and Colour. Drag its edges to resize — the column count follows the height. Scroll with the scrollbar or the arrow / Page / Home / End keys.