The slab, which forms the top of a table tomb (a raised, altar-like grave monument resting on stone supports), lies in the mortuary chapel at the south-eastern end of the graveyard belonging to the Franciscan abbey in Athlone. It is decorated in a style typical of post-medieval Irish memorial carving: a vertebrate border of intertwining stems and fleur-de-lis rendered in false relief, with two oval medallions set within a rectangular frame, foliage filling the triangular spaces at the corners.

The earliest inscription, cut into the left medallion in Roman capitals, commemorates Brian Mac Ganley and his wife Benmon. At some later point, the right medallion was put to use for a second commemoration, recording the death of Chris Ganly on the 16th of March 1701 and naming his wife Ann Ryan alongside him. The relationship between Brian Mac Ganley and Chris Ganly is suggested by the shared surname, the spelling having shifted across the generations in the way Irish names often did when rendered into English. Then, in what may be the most striking intervention, the left end of the slab was physically smoothed down to create a fresh surface, and a third inscription was incised there: a prayer for the soul of Mark Begg, who died on the 11th of August in a year that is only partially legible, at the age of thirty-six, with his wife Margrett Mc Dermott named beside him. The partial date and the deliberate reworking of the stone give the slab an unusually layered quality, three separate acts of remembrance accumulated on one piece of limestone over what may have been several decades.