you must write me a good long letter after you get this, you have nothing ……
you must write me a good long letter after you get this, you have nothing else to do,and though it might not seem interesting to you after you have witten it.it would be a good deal of company in this busy wilderness.
here,what does "a good deal of company"mean ?

Question

you must write me a good long letter after you get this, you have nothing ……
you must write me a good long letter after you get this, you have nothing else to do,and though it might not seem interesting to you after you have witten it.it would be a good deal of company in this busy wilderness.
here,what does "a good deal of company"mean ?

Answer

company = other people around; friends or family
Some expressions:
keep good company = have good friends
keep bad company = have bad friends (drinkers and drug users)

When friends come round then you have company, and you don't fell bored or alone.
Such is the effect of a good long letter from a dear friend or relative.