One important feature of the FITS binary table (BINTABLE) format is that each element of the table (i.e., the intersection of a row and a column in the table) is not limited to a scalar value and may instead contain a vector of data values. Consequently, one can construct a binary table in which each row contains one or more columns containing images. In principle there is no limit to the number of images that can be stored in this way in a single table. Other columns in the table can be used to store other information associated with each image, such as the date of the exposure or the exposure duration. This format is particularly useful for compactly storing a set of logically related images in a single file, rather than storing each image in a separate FITS file. Note that the TDIMn keyword (where n is an integer column number) is used in this case to specify the number and size of the dimensions in the vector column. Usually, all the images in a given column of the table have the same dimensionality, but one can use the variable-length array feature in binary tables to store different-sized images in the same column.