They maybe temporary files created by a program, for example if the source file was an obz, the program may have uncompressed the contents into a temporary file before processing. Another possibility is the recovery process found the body of a file without the name so created a temporary name. In addition to following Kerya's post if the file is not too large you could try loading it into notepad to see if the contents are readable (eg obj) or they contain a readable signature at the beginning of the file.