SeaTable exports bases to DTABLE files as an export format. DTABLE files can be used for backup as well as for migration from one SeaTable system to another.
DTABLE files are container files. A DTABLE file contains a JSON file and an asset folder at the top level. The former contains all tables, their layouts and the values of all columns except the image and file columns. The contents of these two column types, i.e. data in file form, are in the asset folder and are linked from the JSON file. The plugins of a Base are also stored in the Asset folder or a subfolder of the same name.
With compression programs (e.g. the open source 7-Zip) you can "look inside" DTABLE files. This way you also have access to the files stored in the three subfolders of the Assets folder - Images, Files and Plugins.