Since the only software you are trying to use is (arcview) 9.3 you will need to do several things.
1. Convert the records to points.
2. convert the points to lines.
3 set the document crs so that you can calculate miles.
I'll explain the needs in each step.
you have what loooks like an electronic spreadsheeet of the data.
You will need to format that so that it is in row form.
(that is each row represents a specific point) You can include the column headings as you have above.
however it should be one continuos row all the way across.
I realize you probably just formatted the pdf for display. just trying to be clear.
To me it looks like the best value to place points with would be the local easting/northing values.
the lat lon values are ony 2 decimals you need at least 6 to get any accuracy, and as you have local easting (looks like meters?) that would be good.
When you add the spreadsheet (or csv) to arcgis you will right click on the table.
(you can find the table by swithing the TOC to data mode)
Select "display xy data" in the right click flyout.
Now you will be presented with a dialog showing 2 fields which you can modify (Plus a z if you are interested).
choose the localeasting (probably will be truncated to 8 chars) as the x value, and localnorthing as the y. Set the CRS to predefined> GCS> World> WGS84 as the projection.
Now I would export that data to a shapefile...
Right click data> export. choose a folder (make sure you know where)
you can say yes to add it to the map.
Now Unless you have some other tools to use you will probably have to manually connect all the points.
I think et-tools has something for free
Something you said made me think you only want the total length of a siesmic line in a polygon.
So you will need to break each line at the intersection of the polygon edge.
Actually on re-read you will need to decide what lengtht\ it is you are looking for.
the length at each point or just a total length in each polygon.
If the sec cond is true create a line goinng through each point (use snap) and break (split) each one at th epolygon edge.
If the first condition is tru you will need to break the line at each point.
Next you should set your project crs to a unit that can be connverted to miles. (feet preferable). Make sure that you have a field (double 0,0) in your shape file called length.
Add a new field called len_mile (double 0,0)
Right click and calculate geometry on the length field.
NOTE: you can only calculate decimal degrees or the units of the active data frame CRS. (which you just set to feet.)
Select that option.
Now you should have feet in your length field.
Now right click on the len_mile field and select field calculator.
now select the length field and add it to the expression, with / 5280
select ok and you should end up with decimal miles in the len_mile field.
If you need to display miles in easy to read terms you can use the
(Round [len_mile], 2)
Function. This will not change the value but display it with 2 decimals.
HTH