The RecordAction object/entity works with the Actions & Recommendations component in Salesforce Lightning Experience.

When an action is deleted that is referenced in an ActionDefinition or FlowDefinition, the RecordAction record is also deleted. RecordAction records are also deleted when the associated parent records are deleted, or when a flow is paused and the current record context has changed. When an action is completed, the associated RecordAction record gets deleted.

If the RecordAction records are deleted, then the records specific actions built and in progress using the Action & Recommendations component will be lost.

https://developer.salesforce.com/docs/atlas.en-us.object_reference.meta/object_reference/sforce_api_objects_recordaction.htm

To delete, you can use the following apex code.

delete [
	SELECT Id 
	FROM RecordAction 
	LIMIT 10000
];