With Lookup Helper you can automatically relate Opportunity Products to the Account the Opportunity belongs to.
To achieve this, just follow these simple steps:
Create new Lookup Helper setting.
Select Opportunity Product as the child object.
Select the 'Create New Lookup Relationship' option.
Select Account for the parent object.
Name the new lookup field.
Select Opportunity (opportunityid) >, then Account ID (Account) to set the child matching field. This sets the child matching field to the ID of an Opportunity Product's parent Opportunity's Account ID value, also known as a foreign key.
Select Account ID to set the parent matching field.