I recently came across something that seems to contain an exact answer to this question.
In 826, an exiled Danish king, Harald Klak visited the court of Louis the Pious with his wife and some followers, at what would become part of East Francia in 900. They were baptized by the Carolingian emperor, who according to Ermold the Black then held a lavish feast for the newly Christianized Danes. Ermold apparently described the seating at the feast in some detail in his Carmina in honorem Hludowici Caesaris.
Unfortunately I can't locate an English translation, and my Latin is, to put it mildly, really bad. Hopefully someone better at Latin could look into this. In the meantime, though, it seems at least Louis' queen, Judith of Bavaria, was present at the feast.
Discubuit laetus, lateri Iudith quoque pulcra Iussa, sed et regis basiat ore genu.
If I am not mistaken, this proves men and women did feast together in East Francia, specifically after baptisms, and in the general time period requested.
More generally, there doesn't seem to be any evidence for gender segregation at Frankish feasts as Wikipedia implied. In fact, we have some literary evidence of women playing key roles in hospitality events:
Hospitality, too, was an important form of gift exchange, and we have occasional references to queens organizing or presiding over feasting. It is likely that noblewomen, too, were involved in such exchanges within their own households.
Bennett, Judith M., and Ruth Mazo Karras, eds. The Oxford Handbook of Women and Gender in Medieval Europe. Oxford University Press, 2013.
For example, from nearby Flanders, the Vita Rictrudis - written in 907 by the musician Hucbald - records that the eponymous heroine hatched a plot in which:
She encouraged the king to imagine that she wanted to yield to his will and arranged a banquet of sumptuous splendor suitable for a king at her estate in the villa called Baireius. She invited the king and his optimates and, with the salty seasoning of the banquet, they all enjoyed the sweetness of her talk.
Garver, Valerie L. *Women and Aristocratic Culture in the Carolingian World. Cornell University Press, 2012.
This obviously cannot be possible unless they feasted together. That such an arrangement did not merit comment by the author or arouse suspicion in the king indicates it was not considered unusual, at least by the Frankish author.
Moreover, this wasn't restricted to hosts. In the mid-900s poem Waltharius, the poet-monk Ekkehard depicts the heroine Hildegrund as participating in a feast Walther threw for the Huns:
Hildegund played a key role at the feast, drinking and acting normally, thereby helping to lull the guests into a false sense of security . . . [Walter] relied upon Hildegund to help create the festive atmosphere of the banquet in order that he might take advantage of social expectations.
Garver, Valerie L. *Women and Aristocratic Culture in the Carolingian World. Cornell University Press, 2012.
This is, again, obviously not possible unless women's presence at feasts was not considered out of the ordinary, or else it would've been far less suspicious to not have her appear at all.
Note that despite the poem's setting, the author - a monk of noble birth from modern German-speaking Switzerland - was evidently unfamiliar with actual Hunnic culture, and so transplanted the social norms he would've grown up under instead. This passage is thus an illustration of Frankish practices familiar to the author.
While I wasn't able to identify specifically Saxon examples, the evidence indicates that this is common practice throughout the Frankish realms, including East Francia, around 900 AD. It thus seems quite unlikely that Old Saxony would be different from all the surrounding regions.