Relationship Creation for Data Model Memory Error

I am trying to link multiple tables together for my datamodel which are on separate sheets due to not fitting on one excel sheet. One to many relationships have been created by default, although I only need these to be one to one relationships. I need to create this datamodel in order to make pivot tables using information from all the tables on all the sheets (roughly 20 in total). However, when trying to create a relationship between certain sheets I am getting the error message "a record was encountered that exceeds the maximum page size of the storage object excel relationship". It is also using up a lot of memory when trying to create these relationships and has taken upwards of 20 minutes to make 2 relationships successfully.

Are there any possible solutions to this/other ways around this issue?
Each table starts with a column which contains 5 character identification codes which I am trying to create the relationships between.

Thanks in advance for any help with this!