I'm trying to create a table environment similar to memoir's \autorow, (in that I can supply contents as a list, along with the number of columns) but with more complex requirements. I need to be able to use a custom column (similar to what I might do with \newcolumntype) so that I can add automatic custom numbering for each cell. I need to be able to specify an explicit width (let's call it x) for the table, and have items added to the table such that if adding at item to a row would cause that row's total length to exceed x, that item is instead added as a as a column-spanning cell in the next row. An item so long that it exceeds x even if placed in the first column should be allowed to overflow, or wrap within that cell/row. Rows should be left aligned. Here's a mock up illustrating the desired results:

I achieved the auto-numbering using the solution to this previous question.
I realize the solution to this is probably very complex; just knowing what approach to use would be a big help, since I expect an explicit solution probably well exceeds what would be reasonable to ask of someone else volunteering their time to write. Of course, if there's some simple solution I've overlooked, fantastic.

taskspackage. Another possibility would perhaps be theshortlstpackage. See examples of its use with some patching I did on this thread. – Bernard Apr 03 '15 at 00:41tabu. Avoid it like the plague. – cfr Apr 03 '15 at 01:06