Hello Ignace and Olivier,
Please find enclosed a program to reduce the size of TPXO global solutions to smaller areas (e.g. rectangles of a few degrees for length and height).
It is written in Fortran and has to be compiled before used.
Then run name_of_program < input.par with input.par an example of names and coordinates to fill in (please give integer values for min/max latitudes/longitudes).
For a reason I do not understand currently, the results with original TPXO tidal solutions are not exactly the same as with the lighter input files (sometimes a few cm for water depth close to boundaries) but if it can help you to run your computation, feel free to use.
Hope this helps,
Chi-Tuan