To get some sense of how Easter was calculated after Dionysius by people who lacked computers (or even Arabic numerals), I here transcribe an actual table from a manuscript written in 1004. I will reproduce it as exactly as I can, including abbreviations.

from Berne Stadtbibliothek, Cod. 87, fol. 18.

B	M iiii	ii	xxvi	vi	xiii	v id aprl	xvi kl aprl	xxi
	M v	iii	vii	vii	xv	iiii kl aprl	kl aprl	xvii
END	M vi	iiii	xviii	i	xvi	xv kl mai	xi kl mai	xviii
	ANNI DNI	INDICT	EPACTE	CCVRR	CICLLVN	XIIIIma LVNA	DIES DOM POST	LVNA IPSIUS
	M vii	v	Nvlla	ii	xvii	Non aprl	xvii id Aprl	xv
B	M viii	vi	xi	iiii	xviii	viii kl aprl	v kl aprl	xvii
	M viiii	vii	xxi	v	xviiii	Id april	xx kl mai	xviii
	M x	viii	iii	vi	i	iiii non aprl	v id aprl	xxi
	M xi	viiii	xiiii	vii	ii	xi kl aprl	viii kl aprl	xvii
B	M xii	x	xxv	ii	iii	iiii id aprl	id aprl	xvii
	M xiii	xi	vi	iii	iiii	iii klaprilis	non aprl	xx
OGD	M xiiii	xii	xvii	iiii	v	xiiii kl mai	vii kl mai	xii

 
So, what does it all mean? Let's start with the column headings, which in this case actually come in the middle of the table. Expanding the abbreviations, the headings mean: anni domini (years of the lord); indictiones (indictions); epactæ (epacts); concurrentes; cicli lunae (lunar cycles), 14^ma Luna (the 14^th moon); dies dominica post (the Sunday afterwards); luna ipsius (this moon).

The indiction we have already seen. It plays no direct role in the calculation of Easter, but note that the cycle remains consistent with that given by Dionysius. The epacts indicate the age of the moon (i.e. days into the lunar month) on March 22, the earliest possible date of Easter Sunday. The concurrentes give the day of the week (the so-called ferial numbers) of March 24th. The lunar cycles track the Metonic, 19-year cycle. Later in the Middle Ages, this cycle will be determined by the numerus aureus, the golden number, so called because it is the key to figuring out the date of Easter. Note, however, that this lunar cycle, while it has the same practical effect as the golden number, is not exactly the same. For example, 1010, which has a golden number 4, is listed as the first year of the lunar cycle. The 14^th moon is the 14^th day of the lunar month, i.e., the full moon. The Sunday afterwards is Easter. The "moon itself" is the age of the moon, i.e., the day of the lunar month, on Easter.

Apart from the numbers and dates, the other abbreviations in the margin are B, for bisextilis, i.e. a leap-year; END for endecadas and OGD for ogdoadas mark the subdivisions of the Metonic cycle. The first is a period of 11 years, the second of 8. They coordinate the insertion of lunar leap.

Translated Medieval Easter Table

	Year	Indct	Epct	3/24	Gldn#	Full Moon	Easter	Moon on Easter
L	1004	2	26	6	14	April 9	March 17	21
	1005	3	7	7	15	March 29	April 1	17
	1006	4	18	1	16	April 17	April 21	18
	1007	5	0	2	17	April 5	April 6	15
L	1008	6	11	4	18	March 25	March 28	17
	1009	7	22	5	19	April 13	April 17	18
	1010	8	3	6	1	April 2	April 9	21
	1011	9	14	7	2	March 22	March 25	17
L	1012	10	25	2	3	April 10	April 13	17
	1013	11	6	3	4	March 29	April 5	20
	1014	12	17	4	5	April 18	April 25	21

 
If you check these years (for example with the ChurchCalendar applet) you will find only one (March 17) is wrong. This one is an obvious scribal blunder. Easter must come after the full moon. The scribe wrote 16 Kalends of April when he should have written 16 Kalends of May, which is April 16, the correct date. Further, if you calculate the week day of the 24th, you will find that all of them match up correctly (1 = Sunday, etc.).