In fact the geometry includes triangular faces. The edges which is common in two adjacent triangles are not changing during the design process. So instead of storing actual point data (x,y,z) I store the edge id the second column and the proportion length of the point along the edge (yellow) column. Every point data corresponds to some geometry data which is also stored in two columns after the yellow column. What you see here the data of a six face geometry. Yes it has only four rows because the six face has only 4 common edges, and the geometry always put only on common edges only. On the next screen you can see the current solution for editing the geometry, With the circular control knob I change the point location on the edge and with the sliders additional geometry data. When the point reach the appropriate position, or I change the geometry sliders I push on of the corresponding Boolean buttons and data is written to the corresponding row of the excel sheet. Maybe you can see the problem now. This is an example of six face geometry, but the real ones can be 200-500 faxes. At this amount of data excel read write is very slow I guess primarily because grasshopper reads the whole excel table when it changes. It would be nice if I could arrange the grasshopper could handle only those excel rows which are changed, not the whole excel table. I am looking for any solution which works quicker than the current one.
