Which element has larger atomic radius -- beryllium or xenon?
You cannot really effectively compare the atomic radii of xenon and beryllium empirically; the atoms are too far apart. Once you remove yourself from direct neighbours, it is generally not possible to estimate relative sizes of atoms.

The closest hint you can get are calculated atomic radii on Wikipedia’s data page. These show that xenon is slightly smaller ($\pu{108 pm}$ to $\pu{112pm}$) but the difference is smaller than the expected error. So, for all intents and purposes they have the same size.