there are two possible answers to this question that seem plausible to me.
1) A Renaissance man: named after the era famed for creativity and development in a wide variety of areas
2) A Jack of all trades, master of none: derived from the status one would achieve in their chosen trade; a master would be part of a guild for a certain trade while his 'jack' would be his apprentice or assistant in training.
You could call that person a polymath (it does not mean mathematician), a Renaissance Man or Renaissance Woman.
Polymath
Accomplished
Dot com man
The person who buses tables in a restaurant is often called a bus boy/girl. Other names for this position are server or waiter/waitress.
Often called a wire, except international telegrams are often called cables.
A person who aquires art for a gallery, museum or private company is called a curator. But these people are not art collectors in the same sense as an ordinary person who buys a lot of art is termed an art collector. A person who gives financial assistance to an artist is called a benefactor, but again, though benefactors are often collectors the two terms are not synonymous.
A very small kitchen is often called a kitchenette.
theoretical
Polymath
I've heard them called a "renaissance man/woman" If they are older, and have lots of practical knowledge in a field, sometimes they are referred to as a "geezer tech."
A person who is knowledgeable is often referred to as an expert, scholar, or well-informed individual in a particular field or topic.
A person who learns a lot is often referred to as a scholar, a knowledgeable individual, or simply well-learned.
One term for a person blessed with wisdom is a "sage." This individual is highly knowledgeable, insightful, and often sought after for their wise counsel and guidance.
A depraved person is often called wicked, corrupt, or immoral.
A person who studies prison management is often referred to as a criminologist or a corrections officer. These individuals are knowledgeable about various aspects of the criminal justice system, including the operation and administration of prisons. Their work involves understanding and implementing policies and practices to manage and rehabilitate inmates effectively.
ambivalent
A person who studies the human brain is called a neuroscientist. They specialize in understanding the brain's structure, function, and its impact on behavior and cognition.
Elysian Fields is a world which is often attributed to Greek mythology. It is said to be somewhat like Heaven where gods, some mortals, and heros live when they die. Whether it exists or not will differ from person to person. Most people will simply believe in Heaven.
An erudite scholar is someone who is highly knowledgeable and well-educated in a particular field or multiple fields of study. They are often recognized for their depth of understanding and ability to engage in sophisticated intellectual discourse.
A person from Gibraltar is called a "Gibraltarian" and Gibraltarians often also call themselves Llanitos.