Thanks to all. I have made significant progress, if only in understanding; but steady with this novice ... increasingly so on all things PC, net, and iPad. Only 10 yrs in retirement and everything has changed!
The problem has been the poor understanding of my problem, which has been enlightened with the advice above.
iPad meets my need to read documents and access the internet, opposed to previous PC based creative activity. No need for PC / Mac ... I think. PC required by remote daughter so I will not have access.
500 Gb of files on PC, primarily pdf, ppt, doc, and photos. Required to be read on an iPad, or massaged within the limits of free Apps, but stored off the iPad. Currently using free Acrobat and M/S Apps with success; files transferred slowly via mail attachments.
Now considering Dropbox or similar; need to read-up on Drive, iCloud Drive, etc - iPad access OK, but what about upload from a PC?
I note possible problems with file titles - my PC titles are often symbolic to denote usefulness (_ _ or *), then the normal alphanumeric descriptors with date ordering, but this irritation can be overlooked for iPad use. I suspect a tedious iPad search and file renaming after I have solved the access without PC storage.
Network Attached Storage (NAS) sounds interesting, but my knowledge of that is no more than this mornings reading of Wiki (increasingly novice like understanding of PC, wifi, and iPad). There appears to be several Apps associated with such systems.
An immediate thought / question. Could a 1Tb backup drive containing all PC files in their original formats (uncompressed / no back up massaging) be plugged in to a router, e.g. dreaded BT Hub 5, via USB?
Would an App be required for access, or would the iPad be able to see the files directly, like from the web?
I am tempted to 'try this at home', but will wait for further advice.