Tablets of my heart
This is a version of the phrase “tablets of the mind” from line 790 of Aeschylus’ play Prometheus Bound. In the play, Prometheus prophesizes Io’s future wanderings in order that she may remember her fate “in the tablets of her mind.” However, Mr. Crawley uses this phrase to say that he will keep in mind the trust and friendship of Mr. Robarts. [AM 2006]
Sources: Aeschylus, Prometheus Bound 788-789.