A document here, CIVIL WAR ACCOUNTING PROCEDURES AND THEIR
INFLUENCE ON CURRENT COST ACCOUNTING PRACTICES ,by Darwin King and Carl Case, has information which explains most of what you are asking about.
(As pointed out in comments, Off is officers, and EM is enlisted men.) Some of the other terms are discussed here:
The Morning Report Book, in addition to listing the men available for
duty, also listed any soldier who was under arrest, away with or
without leave, killed in action, wounded, hospitalized, or sick.
This 'Morning Report' is the source for the information in your book, mentioned as 'the brigade morning report for January 10'.
Concerning the terms FOR Duty and Det Svc:
The Sick Book was updated every morning reporting the names of all ill
soldiers. It included a statement by the surgeon as to whether they
were excused from active duty or available for duty. “For duty” meant
that the man was fit and able to perform all of the typical duties of
a soldier including guard duty, drills, parades, and detached service
(Kautz, Clerk, 15). Detached service was a situation where soldiers
were sent away from their companies to perform duties at another post,
camp, or garrison (Kautz, Customs, 43).
Extra duty is also explained in this report:
The Morning Report Book was prepared and sent to the regimental
adjutant’s office after sick call but no later than 8 am daily. The
book contained the duty status of each soldier in the company. It
included a “Remarks” column that described the reason for every
officer or soldier not being available for duty. This document also
described the situation of any soldier on “special or extra duty.”
Extra duty was a situation where soldiers were assigned to some
continuous labor, in addition to their normal duties, for a period of
ten days or longer (Kautz, Customs, 43). The most typical situations
included employment in the Quartermaster’s department as mechanics,
laborers, or teamsters.