It is important to distinguish results that apply only in the limit of a large matrix size $N$, from results that apply for small $N$ as well. The theory of random matrices addresses both large-$N$ properties as well as small-$N$ properties, and there are physical applications in both regimes.   

 I understand from your question that your interest is in large-$N$ properties of the GOE. Then "bulk" versus edge refers to the support $(-W,W)$ of the <A HREF="https://en.wikipedia.org/wiki/Wigner_semicircle_distribution">Wigner semicircle,</A> rescaled such that $W={\cal O}(1)$. The transition from bulk to edge region is at a separation of order $N^{-2/3}$ from $\pm W$. The deviation of the eigenvalue density from the Wigner semicircle in the edge region is described by the <A HREF="https://en.wikipedia.org/wiki/Tracy–Widom_distribution">Tracy-Widom law.</A>

But do keep in mind that the theory of random matrices is not restricted to the large-$N$ regime. For example, chaotic scattering from a billiard with an $N\times N$ transmission matrix is described by the circular ensembles for any $N$, even as small as $N=1,2,3,\ldots$. In that case there is no notion of bulk versus edge, but there are universal properties that can be measured in experiments, such as the $T^{-1/2}(1-T)^{-1/2}$ distribution of the transmission probability $T\in(0,1)$ for $N=1$.