That license is the Unicode license from http://unicode.org/copyright.html . I don't include the character data verbatim, but I have a set of headers derived from them, for example https://github.com/patperry/utf8lite/blob/master/src/private/charwidth.h . These are generated from the python scripts here: https://github.com/patperry/utf8lite/tree/master/util .
I have listed "Unicode, Inc. (Unicode Character Database)" in the Author field per the CRAN policy, and I believe that the current package description is compatible with the Unicode license. If you have suggestions for how to better document the license situation in the package, please let me know.