First, there were separate firing tables for each artillery piece. So, a 105mm had different tables from a 155mm, and two 105mm guns might have different barrel lengths, needing separate tables.

So, the firing tables for a 105mm howitzer were published under FT 105-H-6. This included tables for eight different rounds, from High Explosive to Smoke to Illumination. Each round type has a different weight, and therefore a different table.

There are three variables that the gun crew has control over: Elevation, powder charge, and fuse time (when using a timed fuse). The 105mm had 7 powder charge possibilities, the base charge and 6 additional bags that could be removed.

The relationship between range, elevation of the gun tube, and powder charge gives you options as to time of flight and angle of impact. You might want a higher, longer flight to get the shell over an intervening hill or into a trench, but choose a shallow flight to hit a bunker viewport.

Time of flight determines the wind drift, expressed in yards of drift per 1 knot of crosswind. Time of flight is also used to get the first shell of a barrage to arrive simultaneously from widely separated batteries (Time-on-Target).

The purpose of ENIAC was take all these variables and produce tables (and sliderules) for the artillery fire direction center and batteries to quickly get steel on target. You choose the table for the gun-round-charge combination, and use the range to compute elevation and wind correction.