What happens if we look at astronomical tables not as artefact which embody such or such astronomical, cosmological or astrological theory but more crudely as the product of mathematical computations? In terms of quantitative analysis the first point of view often amount to dig out astronomical parameters from the tables, while for the second perspective the questions becomes: how numerical values of the tables were computed? This look at astronomical tables from the point of view of the history of mathematics is growing both on the “practical turn” of the history of mathematics and on the development of more and more refined quantitative techniques to analyse tables by the historians of astronomy.

This presentation will first draws from the existing literature some of these quantitative techniques developed with various aims but which may be used by the historian of mathematics to recover ancient mathematical practice from astronomical sources, before discussing some of my works in this direction mainly on the Tabule magne of John of Lignières and on the Tabule permanentes of John of Murs both made in Paris between 1320 and 1330 . From these first attempts we will give provisional conclusion on the achievable aims of such studies and on their potential signification both for the history of mathematics and astronomy.