A Numbers sheet is a blank canvas: several small tables, a chart and some text can float anywhere on it. Excel has no canvas, just rows and columns. Choose how to fit the tables into Excel and see where each lands, including what happens to formulas that point between them.
We converted one source document into every major output format and measured the file that came out. The source was a 37.4 KB DOCX with headings, bold and italic text, a table, numbered and bulleted lists, and one embedded image.
Sizes are from one representative document converted with Pandoc and LibreOffice. Your own files will differ, especially with more images, but the relative ordering holds.
A PDF has no paragraphs. It stores “draw these glyphs at x, y in this font”, often one word or one line at a time, and a scanned page stores only a picture. Drop any PDF to see which kind you have and what its page instructions look like.
Values and ordinary formulas always survive. These are the Numbers-only features worth checking before you send the file to someone on Excel.
Neighbouring tools, with a typical result for each.