Hi Reginald,

1.  One way you can do this is by first running a Summary Statistics on the table to summarize by the LOT field.  For the Statistic, you can choose any other field and statistic value:

2.  Add a TEXT field to this output table (i.e. OWNER).

3.  You can then execute the following python script.  You will want to update the Variables to the directory/database, original table, and the output table from the Summary Statistics tool.

import arcpy
from arcpy import env

#Variables
env.workspace = r"C:\TEMP\PYTHON\User_Data\Data.gdb"
origTable = "test"
sumTable = "summary_stats"

# Get a list of LOT IDs
idList = []
with arcpy.da.SearchCursor(sumTable, ["LOT"]) as cursor:
    for row in cursor:
        idList.append(row[0])
del cursor

idList = set(idList)

# Iterate through each LOT
for id in idList:
    # Use a search cursor to query only the individual LOT
    with arcpy.da.SearchCursor(origTable, ["OWNER"], "LOT = {0}".format(id)) as cursor:
        for row in cursor:
            # Use an update cursor to update the OWNER field
            with arcpy.da.UpdateCursor(sumTable, ["OWNER"], "LOT = {0}".format(id)) as cursor2:
                for row2 in cursor2:
                    if row2[0] == None or row2[0] == '':
                        row2[0] = row[0] + ", "

                    else:
                        row2[0] = row2[0] + row[0] + ", "

                    cursor2.updateRow(row2)
    del cursor, cursor2

# Remove the trailing commas in the fields
with arcpy.da.UpdateCursor(sumTable, ["OWNER"]) as cursor:
    for row in cursor:
        row[0] = row[0].rstrip(', ')
        cursor.updateRow(row)
del cursor