To get a list of all the properties of a Type, which is equivalent to listing all the columns of a table, you can use the Type.known_properties() function, where Type is the Type you are interested in.
model = rai.Model("PeopleModel")
# Declare Person type.
Person = model.Type("Person")
# Define some Person objects.
with model.rule():
Person.add(name="Alice", age=20)
Person.add(name="Bob", age=15)
print(Person.known_properties())
# ['name', 'age']
Read more about Type.known_properties() in our documentation.