I guess more details are needed - some ideas you may try:
First, issue a file
command for the file. It will probably tell you what type of file is.
jim@debian:~$ file foo.bar
foo.bar: ASCII text
Second, search for similar files and see if there's a program to open them in the machine - maybe, they are binary files for some program out there, and you just don't know which one.
Last, but not least, I believe you are right - looks like HTML code to me, so maybe this is used by an application as a kind-of intermediate language, that is parsed later to transform it to real HTML.
I hope this helps!