You could read that table as csv with Python.
If your lots have matching LotIDs, you could use ce.getAttribute to grab the shape's LotID and use that to match the loaded csv lines and then use ce.setAttribute to append them to the shapes.
If you don't (meaning you only have your coordinates), you could instead use ce.getPosition to get the shape's position and (with some fiddling) use that as match attribute.
However:
- the values will probably not match perfectly so you'll have to use a search radius (yuck, math)
- you probably have to convert between coordinate systems, as CE returns position in meters (yuck, much more math)
Easy solution: do it with a desktop GIS system (there are some free ones too, like QGIS), or ask someone to do it for you. It would take like five minutes. All you'd have to do is convert the XY table data to a point shape and then do a spatial join with the lot polygons.