What Excel is
An Excel workbook is a zip archive of XML parts describing sheets, cells, formulas, styles and charts. The .xlsx extension is that format; .xls is the older binary one from before 2007.
Finance, operations and anyone who received a file from finance or operations.
What Trac Wiki is
Trac wiki tables use double pipes around every cell.
Projects still running a Trac instance.
What changes when you convert Excel to Trac Wiki
Only the first sheet is read, and cells are read as the text Excel displays rather than the number underneath. That matters for dates: a cell showing 15/03/2026 arrives as that string, not as a serial number you would then have to decode.
Every cell is wrapped in double pipes, which is the whole syntax.
What carries over from Excel to Trac Wiki
Excel records 4 things about a table that Trac wiki has no way to hold.
Excel distinguishes a number from the text of a number; Trac wiki does not, so every value arrives as text and has to be re-parsed by whatever reads it next.
An empty cell and a missing one are the same thing in Trac wiki, so a null and an empty string in the Excel both come out blank and can no longer be told apart.
A line break inside a cell ends the row in Trac wiki, so line breaks are replaced rather than carried through.
Trac wiki marks its header cells differently from its data cells, so the first row is written with that marker.
Anything visual in the Excel - weight, alignment, colour, column widths - has no counterpart in Trac wiki and is dropped. The values are what survives.