Joining two tables with different fields through a link-table
People and Events are related thorugh a many-to-many relationship, because an event can have many people related to it, and one person can be related to several events. 

This is represented in a SQL database by means of a link-table, which contains (at least) two columns (fields), one indicating the unique id representing the Event, the other one indicating the unique id representing the Person (People). Let's call those columns EventId and PeopleId. The table might contain more columns if they should provide some relevant extra information (let's say you want to know which role the person had with regard to this event, such as "was the organiser", "was an attendant", "was a sponsor", "was the inducer", "led the event", "was one of the lead roles", "just was a passer-by", "was the victim", ...).

The primary key of this table is actually a compound one, comprising both (EventID, and PeopleID). So your table should be defined in a fashion similar to the one depicted in the following image:



You can let Access know how this table is related to the other ones by means of the Relationships Diagram:



The corresponding SQL definition is:

CREATE TABLE [People_x_Events] 
(
    [PeopleID] LONG NOT NULL REFERENCES [People] ([ID]),
    [EventID]  LONG NOT NULL REFERENCES [Events] ([ID]),
    PRIMARY KEY ([PeopleID], [EventID])
) ;