[R] Insurance data in library(MASS)

[choonhong ang]

I have used the insurance data from R library and I have 2 questions:
I use the following:
>library(MASS)
>data(Insurance)
> m1=glm(Claims ~ District + Group + Age + offset(log(Holders)),data =
Insurance, family = poisson)
>summary(m1)

Call:
glm(formula = Claims ~ District + Group + Age + offset(log(Holders)),
    family = poisson, data = Insurance)
Deviance Residuals:
     Min        1Q    Median        3Q       Max
-2.46558  -0.50802  -0.03198   0.55555   1.94026
Coefficients:
             Estimate Std. Error z value Pr(>|z|)
(Intercept) -1.810508   0.032972 -54.910  < 2e-16 ***
District2    0.025868   0.043016   0.601 0.547597
District3    0.038524   0.050512   0.763 0.445657
District4    0.234205   0.061673   3.798 0.000146 ***
Group.L      0.429708   0.049459   8.688  < 2e-16 ***
Group.Q      0.004632   0.041988   0.110 0.912150
Group.C     -0.029294   0.033069  -0.886 0.375696
Age.L       -0.394432   0.049404  -7.984 1.42e-15 ***
Age.Q       -0.000355   0.048918  -0.007 0.994210
Age.C       -0.016737   0.048478  -0.345 0.729910
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
(Dispersion parameter for poisson family taken to be 1)
    Null deviance: 236.26  on 63  degrees of freedom
Residual deviance:  51.42  on 54  degrees of freedom
AIC: 388.74
 (1) In the result above, what is Group.L, Group.Q, Group.C, Age.L, Age.Q,
Age.C ?

 (2) When I copy the Insurance data in csv format (as shown in the
attachement) and run the same procedure the result shown is different from
above result, why ?