According to the proportion, or, empty place, i.e. according to the bigness of the spaces which were left empty for them, implying that they were smaller than those above mentioned.
Related Commentaries of 1 Kings 7:36
1 Kings 7:36
36 For on the plates of the ledges thereof, and on the borders thereof, he graved cherubims, lions, and palm trees, according to the proportioni of every one, and additions round about.