Pylon Benchmark (Pylon Table Union Search Benchmark)

We create a new dataset from GitTables, a data lake of 1.7M tables extracted from CSV files on GitHub. The benchmark comprises 1,746 tables including union-able table subsets under topics selected from Schema.org: scholarly article, job posting, and music playlist. We end up with these three topics since we can find a fair number of union-able tables of them from diverse sources in the corpus (we can easily find union-able tables from a single source but they are less interesting for table union search as simple syntactic methods can identify all of them because of the same schema and consistent value representations).