Let's see.
I would like to see the following-
1. More tables.
2. References to other books that are not yet completed.
3. Even more tables.
4. Appendices; did you know that after you get to the Z appendix, you go to AA appendix? Yeah, that!
5. Tables that cross-reference other tables.
6. Words that I like. Antipathy. Chrysoprases. Libram. Dweomer. Syndicracy. Antipathy. Brazier.
7. Tables that require percentile rolls.
8. Gatekeeping for abilities and classes; you know, like, "You can have psionics if you roll 99-100 on d%," or "You can play a Warlord, Brad, if you are at least 8' tall. Not your Goliath character ... you, Brad."
9. Cooler tables, and more of them.
10. No index. Indices are for PEOPLE THAT KAN'T REED GUD.
11. A lot of crunch that I will not use, like the average tunneling distance of a Norker mine worker, expressed in cubits per fortnight. Preferably in ... a table.
12. Addition of new abilities that are thoroughly incompatible with the base rules. How about a seventh ability! That would be so ... perfect.
13. More tables than Ikea has meatballs ... or tables.
That about covers it.
Have you considered...
https://1d4chan.org/wiki/FATAL
Should have every table you ever wanted... and definitely every table you NEVER wanted.