I have been using Cakephp ver2.x and just started migrating to Cakephp v3.x. When I tried using the new ORM, I am baffled by basic concepts like repositories and table objects. What is the difference between repositories and table objects?
A repository can be anything while a table, as the name states, is just a table.
http://api.cakephp.org/3.0/class-Cake.ORM.Table.html
Represents a single database table.
Exposes methods for retrieving data out of it, and manages the associations this table has to other tables. Multiple instances of this class can be created for the same database table with different aliases, this allows you to address your database structure in a richer and more expressive way.
http://api.cakephp.org/3.0/class-Cake.Datasource.RepositoryInterface.html
Describes the methods that any class representing a data storage should comply with.
A data storage can be any kind of storage system, even one that doesn't know tables like a graph DB or document based system.
It is always simple to just check the API documentation and code for this kind of questions. The code is pretty well documented. Also the way this works becomes obvious then:
class Table implements RepositoryInterface, EventListenerInterface
Table implements the interface defined by RepositoryInterface.