I cut a lemon with a milk knife and then squeezed it onto apple strudel (before cooking). I then put it in a BEN YOMO milk oven uncovered. Can I eat this on Shabbos after meat meal. The amount of lemon in the strudel is very little juice?

The milky lemon juice in the strudel is nullified by the strudel itself if there was 60 times more strudel than the juice. This is the case even though the milky juice on its own was not considered an "issur"( something forbidden from being eaten) at the time it fell into the strudel. (see Rema Yoreh de'ah 99:6) Thus the strudel remained pareve. Though it was baked in a milky oven it may be eaten after a meat meal. Though it should be clear that this is only after the fact and this should not be practiced to begin with.