mathematics – How to make good combinations of xp tables and xp rewards?

Is there a known step by step to define mean xp reward formula/table to base specific challenges rewards and total xp table that set character level progression speed? Sounds complicated.

In addition, I see big xp tables with a lot of rounded digits with no beat missing, looks closely handwritten (just not). Is there a method or algorithm that builds and (perhaps) rounds to maximum with no kink?

For example, a character has about Hp≈(8+2*Lv)², Atk≈(4+Lv)² and Def≈4+Lv. Damage is Dmg = Attacker_Atk*sqrt( Attacker_Atk )/( sqrt( Attacker_Atk )+Target_Def ). If character defeats about LevelUpEnemies(Lv) enemies like self then character grows up. Initial level is 1 and final level is 10 (like WCIII).

How can I calculate (fair) rewards and total xp table to do this?