I am paying for AT&T 3G service and most of the time, I see AT&T 3G indocated on the upper left hand side of the Ipad Display. Sometimes, I see AT&T E indicated? What is this? Is thsi any slower than 3g??

EDGE - which is a 2.5G technology. Not all areas have 3G coverage, and even if an area does, if it is excessively busy sometimes 2G service has a stronger signal. It is significantly slower than any 3G (it can approach 3G UMTS speeds but is much slower than 3G HSPA), but is much faster than 2G GPRS.

Short story - your area is not 100% 3G compliant, if at all.

The Edge system is the backup for 3G. If your area 3G system is overloaded, you will be put on Edge. Other carriers will not have any options. Sometimes Edge is fairly quick, but on average not as good as 3G. However, even with a good 3G system, increased usage of the internet can cause slowdowns anywhere there is a bottle neck.