That's a nice looking tarantula! Very fat for an Old World tarantula.

You can usually identify if the tarantula is going to molt by looking at the abdomen. If the abdomen starts to darken, you can expect it to molt in a few month or so. Also, if the tarantula is fasting for months already, that means it's already in its pre-molt stage.. although it may still eat a few times before molting.