I was thinking if I can open this file in excel...

I'd recommend against doing this. Excel has a nasty habit of rearranging the contents and adding a bunch of extra junk into the file. At least it does on Windows when messing with XML files.

    I can open the file in terminal but it doesn't show up nicely.

My guess here is that either this is a binary file (an example is a .jpg file) or has some encoding that your 'terminal' is not using/expecting. As GrandFather has pointed out, you probably need to find out more about the file format and provide that information before others can offer suggestions on how to read the file.