The Feather file format is a column-oriented binary disk-based format based on Apache Arrow and supported by (at least) Python, R and Julia. Some description of it is available at https://github.com/wesm/feather and https://blog.rstudio.com/2016/03/29/feather/. It can be used for large datasets, but it does not support array-valued columns. It can be a useful format to use for exchanging data with R, for which FITS I/O is reported to be slow.
At present CATEGORY type columns are not supported, and metadata associated with TIME, DATE and TIMESTAMP columns is not retrieved.
This format can be automatically identified by its content so you do not need to specify the format explicitly when reading feather tables, regardless of the filename.