Styling Tables

Can I get some general advice on styling tables? I see that the cell borders don’t display on an ePub compile.

I would also like for the table to be as compressed as possible. I know that ePub files leave font sizes to the reader, but I would appreciate general table advice. I am dealing with two tables; one of which is large, with 17 rows and 5 columns.

To my knowledge, that is not something an epub can support.
If it does, I’ve never seen it.

I think that needs to be rendered as an image.
For example, if you read Stephen King’s novels, there is often a map of the village where the action takes place in the first few pages of the book.
But it (at least seems) to always be in an image format.
Not free to be rearranged. (The size is fixed - proportional to the screen size ; not user adjustable ; impossible to zoom in ; impossible to navigate.)

I’d expect you to have a conflict between the font size set in the Ereader, and the space your table’s cells require.

And by definition, in HTML, vertical lines don’t actually exist. They are just chunks of the desired line impression lined-up above one another.
(But without the line spacing inbetween. Occupying the full height of each required display lines.)
Or outlined cells next to one another, summing up to visually become a table.

On the other hand, perhaps, who knows, since an ebook isn’t much more than a zipped HTML file (like a miniature website, sort of), maybe it could be done… (But I highly doubt it.)

→ Perhaps you could achieve it using ╚ ╝╠ ═ ║ ╗ ╔, spaces and line-breaks. And a lot of patience…
(But then again, if the reader changes his/her line spacing in the e-reader, or opts for a bigger font, it all goes down the t…)