Hi Donald,
You are probably talking about this https://www.genealogieonline.nl/english-immigrant-1200-1500/I719.php tree - which seems to originate from you. The earliest person in this tree is Walter de Bolebec
The first possibility is that this name could come from the village of Bolbec near le Havre in Northern France, and near Normandy. See: https://nl.wikipedia.org/wiki/Bolbec That also does correlate to names like Longueville, Giffard, d'Arques which definitely sound French to me. The name Bolbec seems/appears to be of Germanic origin, see https://sites.google.com/site/heemkringascania/documenten/namen-in-asse/de-naam-bollebeek "Also deep in northern France we find a Bolbec, where Germanic dominated until the 8th century."
https://www.google.com/maps/place/76210+Bolbec,+Frankrijk/@49.6023424,0.1920095,10z/data=!4m5!3m4!1s0x47e04453d8f72e07:0x28b1bef255d2fc95!8m2!3d49.575329!4d0.483881
But the name also sounds to me as it could be originating from Bollebeek, a village is Flanders, Belgium. Old spelling of the name Bolbec in the UK also is 'Bollebec'. The area originally is Dutch-speaking, though the spelling Bolbec or Bolebec in that case suggests French pronounciation of that name. Bollebeek is topographically located near the Belgian capital of Brussels, and also quite near today's language border between Dutch-speaking and French-speaking communities in Belgium. See: https://nl.wikipedia.org/wiki/Bollebeek The name of the village probably comes from 'de Bollebeek' which is a local creek (beek means creek), see: https://inventaris.onroerenderfgoed.be/themas/14619
See also: https://sites.google.com/site/heemkringascania/documenten/namen-in-asse/de-naam-bollebeek This site also suggests that 'Bolle' in Bollebeek - amongst other interpretations - might come from the old Germanic word 'bulna' which means bull.
https://www.google.com/maps/place/1785+Bollebeek,+Belgi%C3%AB/@50.9228682,4.2264004,14z/data=!3m1!4b1!4m5!3m4!1s0x47c3c017cf3a6ce7:0x68460eff75a85395!8m2!3d50.92287!4d4.24391
These pages seem to fill in some blanks in your tree:
In the names I have read I see no clear Scandinavian influence. However, your oldest name 'Walter' is clearly of Germanic origin, and so is probably the name Bolbec or Bolebec as explained above. Walter could very well have originated from Northern France or Belgium.