IPv4 delegations consist of PA (provider aggregated) allocations, PI (provider independent) assignments and other legacy assignments of unspecified status.
The first column shows the /8. Further columns show the total number of allocations and assigmnents for the specific prefix. To enhance readability the header row is repeated.
For background informations see RIPE Labs article.
Data is based on the RIR stats files of the five Regional Internet Registries: