Is possible install Eclipse IDE in Honeycomb? Since Eclipse IDE can run in Linux and the new Honeycomb has a Linux Kernel, can Eclipse IDE run in Android Honeycomb ?

I know that isn't pretty much comfortable coding in a tablet, but I'd want to use for UML modeling.
No.

As you might know, Eclipse has various problems running in different flavors of Linux (which is why Ubuntu has an official repository version of it, and all that).  Android is even worse -- while based on Linux, it's a completely different operating system.  A similar question would be, "Is is possible to install a *nix version of Eclipse in Mac OS?"