What the hell do you do here?

[RTFMy]

I'm stumped.

http://www.rtfmish.com/hl2/d2_prison_050000.jpg

 

[AJM2K3]

first, don't get squished...

look around a little, you'll find the way in...

 

[Solver]

There's a way out on the left. More specifically.

Spoiler

Use the gravgun to set up the table so you can get in there.

 

[Unimatrix881]

If I remember correctly, simply don't get squished. Once the final few of those start to close, you'll see the exit. Just look around, it took me a few trys also, but the game will require thinking, patience and persistance.

 

[Mevoki]

There's a way out on the left. More specifically.

Spoiler

Use the gravgun to set up the table so you can get in there.

Right you are!