Float, Double, Blob?

When adding a field (column) to a table in ArcMap, ever wonder what you should choose for Type?  Text may be obvious, but what about Float, Double, and Blob?  Click on the graphic thumbnail here for a description of each possible data type.

Comments

[Martin Piorkowski]

I have a large about of descriptive text to associate with a data point. I currently have a shapefile with 1059 points all with various amounts of data to be associated with each. I have an Excel spreadsheet with all of this data included. Each row or entry has a unique identifier. The problem is 3 of the colums of data may have a large amount of text in that cell. I've tried joining the table to the ArcGIS shapefile and it displays "Blob" for each of these three colums. How can I have this data displayed, or where is this information being stored? Thanks for any help you may have.