I good way to find out about these things is to check out some existing mods and discussions. SR2 is nearing it's 10th year anniversary and fans had already spent years dismantling it. The reason I mention SR2 is because from a modding perspective, the files had been recycled throughout the series to the point where knowledge from one game can be easily be transferred to another. Take the vehicle handling file for the bootlegger for example: not a single value changed since Sr2 and I bet that file is still hanging around unused in SRGOH. Gentlemen of the Row by Idolninja is a good place to start if you want to see some of the freedom and limitations of Saints Row modding especially with tables. Then checkout some other mod releases, search some questions up on Google (good way to get through the deep useful corners of this forum), check out some mods in progress, tools, etc. Don't let all these old words in this forum be wasted. Reuse, Recycle.
em...difficulty_level.xtbl for stamina, spawn_info_ranks.xtbl for health, and tweak_tables.xtbl for jump height. Check those out. Speed up melee attack: don't know, try melee.xtbl, anim_files.xtbl, or tweak_tables.xtbl.
Hope this helps.