AFTER FOUR MONTHS in office, Virginia Gov. John N. Dalton is proving to be a man of his word. He promised voters a moderate time and that's what they are getting. No one can seriously accuse the governor of being a social or economic activist, which in Virginia politics are considered at least a misdemeanor. Yet Mr. Dalton is by no means asleep at the switch in Richmond: he has acted decisively when necessary.The mystery is what he has in mind in the way of administration policies or goals.

Mr. Dalton did past his first stiff test of leadership impressively: He avoided what could have been a long inflamatory civil-rights dispute with the federal government - by deciding to accept the demands of the Department of Health, Education and Welfare for disegregation of the state's colleges. That was a welcome change from the bravado of his predecessor, Mills E. Godwin.

The government also has been making good of his commitment to run on administration in which black as well as white Virginians and women as well as men, participate at the top levels. He has as well, shown a welcomed appreciation for the concerns of Northern Virginia. For example unlike Mr. Godwin, who look on Metro as some sort of solid-gold, luxury toy for people of a foreign land, Mr. Dalton has stated that the rail system is vital to this area's public transportation system.

What you still can't tell is what the governor thinks he should accomplish over the long haul - or even what he might propose by the time the General Assembly returns next year. Unlike his predecessor, who used to meet the press regularly, Mr. Dalton's general news conference arerare and, when he is asked about future actions, laced with dodges. In a meeting with reporters late last month, the governor was asked to say that major issues he would concentrate on now that his first assembly session was behind him. He answered that he would be attending a Southern Regional Education Board meeting in Florida in June and then proceeded to list the legislators and other state official who would accompany him.

Well, maybe nobody's ready for vision at this point. After all, just the other day Gov. Dalton brought his entire Cabinet to Northern Virginia to hear grievances-as he had promised he would, during the campaign - and only 25 citizens showed up. But there are issues that need addressing, such as state and local revenue responsibilities and annexation. In the meantime, at least, Gov. Dalton has demonstrated that his administration is not merely an extension of the last one - and that in itself is good news.