This dataset contains plain-text numerical data supporting the study “Size-restricted magneto-transport in the delafossite metals PdCoO₂ and PtCoO₂.” It provides the underlying data for main and supplementary figures, documenting directional ballistic magnetotransport measurements and related analyses in these high-conductivity delafossite metals. The dataset is intended to enable verification, reuse, and further analysis of the reported magnetotransport behavior.