[RPG] Does proficiency in both simple and martial weapons mean the character is proficient in all weapons

Firstly, the Ranger proficiencies say "Simple weapons, martial weapons". If you look at the Weapons table, you can see that each category has both melee and ranged weapons in it. The Ranger has every weapon in both categories, regardless of whether it is melee or ranged.

Secondly, the Fighter proficiencies use exactly the same wording as the Ranger proficiencies. "Simple weapons, martial weapons". I don't know where you got "All weapons" from, but the Fighter's and the Ranger's weapon proficiencies are identical.

Finally, if you look at the Weapons table again, you can see that there is no Exotic weapons category in D&D 5e.

A character proficient in simple and martial weapons is proficient in all PHB weapons. For them, other individual weapon proficiencies (like Dwarven Combat Training) don't do anything. There's no difference between a Human Fighter and a Dwarven Fighter in terms of weapon proficiencies.

However, some classes only get a limited number of weapon proficiencies, and this is where racial or other weapon proficiencies come into play. For example, by default a Wizard is only proficient with daggers, darts, slings, quarterstaffs, and light crossbows. A Dwarven Wizard, however, would also be proficient with battleaxes, handaxes, and throwing hammers thanks to Dwarven Combat Training. For that character, the Dwarf's additional weapon proficiencies greatly expand the list of weapons they can use effectively.