I have a custom object called 'Events'. I would like to create a relationship that allows Event records to be related to other Event records. Is this possible using standard customisation?
Just add a lookup field on the event__c object to lookup to itself.
To relate multiple event objects, you need to create a new object called something like
You can then add EventRelationship objects as a related list to the Event layout, showing either the "From" or the "To" or both. And the "New" buttons allow you to wire up new relationships.
(Salesforce counts any SObject row as using 2k bytes of storage space even though you might imaging a simple relationship object would only use a few tens of bytes; only an issue if you have a large number of relationship objects.)