Your description is clear as mud. I presume the table is defined like this -
TABLE DC F'X1,Y1'
DC F'X2,Y2'
TABEND DC F'X3,Y3'
NUMTAB EQU (*-TABLE)/8
This definition will work for either example loop. The NUMTAB symbol calculates the number of entries in the table.
Most beginners are more comfortable with something like this -
LA 3,TABLE
LA 0,NUMTAB
LA 1,25
LOOP1 C 1,4(,3)
BE FOUND
LA 3,8(,3)
BCT 0,LOOP1
...
FOUND ...
More advanced programmers tend to prefer something like this -
LA 3,TABLE
LA 4,8
LA 5,TABEND
LA 1,25
LOOP2 C 1,4(,3)
BE FOUND
BXLE 3,4,LOOP2
...
FOUND ...
In both loops, register 1 is set to the test condition, Another way to code the test would be -
LOOP L 1,4(,3)
C 1,=F'25'
BE FOUND