"Inside" or "inside of"

I've been reading this text:

When you define a type, you can define static data fields within it. The bytes that back these static data fields are allocated within the type objects themselves. Finally, inside each type object is a method table with one entry per method defined within the type. This is the method table that was discussed in Chapter 1.

Richter, Jeffrey (2010-02-05). CLR via C# (Kindle Locations 3546-3548). OReilly Media - A. Kindle Edition.

However, the bolded text made me confused. Should it be inside of instead of inside?

No, inside as a preposition meaning "within the interior of something" is correct here. The phrase the inside of X uses inside as a noun, meaning "interior or inner part". "Inside of each type object is a method table" has minor grammar problems such as no article for inside. One could pedantically, properly, and verbosely say "The inside of each type object contains a method table", but just saying "Inside each type object is a method table" is both correct and direct.

As @jwpat7 says, inside is normally used as a "standalone" preposition. But I don't think there's anything inherently "ungrammatical" about using inside of in this way, and it was certainly far from unknown a century ago...

Today though, unless the context is a noun usage (the inside of something), omit the "of".