The paper reports on the transport characteristics of quantum dot devices etched entirely in graphene. For larger quantum dots (submicron size), the devices exhibit periodic Coulomb blockade (CB) peaks, typical of conventional single-electron transistors (SETs). However, for quantum dots smaller than 100 nm, the CB peaks become strongly non-periodic, indicating significant quantum confinement effects. The random peak spacing and statistics are well described by the theory of chaotic Dirac billiards, suggesting that these small quantum dots exhibit quantum chaos. Short constrictions of only a few nanometers in width remain conductive and show a confinement gap of up to 0.5 eV, demonstrating the feasibility of molecular-scale electronics based on graphene. The study highlights the unique electronic properties of graphene and its potential in various applications, particularly in nanometer-sized electronic circuits.The paper reports on the transport characteristics of quantum dot devices etched entirely in graphene. For larger quantum dots (submicron size), the devices exhibit periodic Coulomb blockade (CB) peaks, typical of conventional single-electron transistors (SETs). However, for quantum dots smaller than 100 nm, the CB peaks become strongly non-periodic, indicating significant quantum confinement effects. The random peak spacing and statistics are well described by the theory of chaotic Dirac billiards, suggesting that these small quantum dots exhibit quantum chaos. Short constrictions of only a few nanometers in width remain conductive and show a confinement gap of up to 0.5 eV, demonstrating the feasibility of molecular-scale electronics based on graphene. The study highlights the unique electronic properties of graphene and its potential in various applications, particularly in nanometer-sized electronic circuits.