If I understand your question, you want to have an incremental row number paired with your results. If this is the case, this is similar to this question and a similar answer applies.
The Splunk command you are looking for here is accum -which increments a field value by one.
index=blah sourcetype=blah blah | eval SNO=1 | accum SNO | table SNO Field1
It should be noted, however, that Splunk will show row numbers in a table by default. The numbering will begin at one (1).
Do you mean serial order or serial number ?
In Splunk the the order is chronological, based on the timestamp.
Or i you want you own order, in your logs, add a columns with an incrementing number.