A report that shows lab results in a columnar format would be very helpful for looking at changes over time.
What I have seen from a couple different practice management packages (such as Epic) has the various test results down the left, (i.e. WBC, RBC, HGB, HCT, etc) the unit of measure in the next column and then the most current test in the next column with a header of the date and lab. Each successive column to the right is the next older test.
The results are generally grouped by things like Vital Signs, Metabolism, Chemistry etc. So in a given column that was CBC it will have those values, but the prior test may have been a Hepatic Panel so it would only have values in those rows.
This is a helpful view since in many cases there is overlap in results from various panels so you can get a good chronological view of those results regardless of if some came from a metabolic panel and others came from hepatic panels or even specific tests.
The current software does an excellent job of collecting lab data but the reporting is so limited that it makes using that data a challenge. While graphs are good for looking at trends of looking for relationships between results, good tabular data is also important where the values themselves are as important as general trends.