please, what does this mean

"Hold up" seems to mean "impede the progress of" in this context. It's not a really clear sentence -- for example, I'm not sure if the fact that the word "supplies" is in quotation marks means that it was a term used at the time for taxes. The quotes might be extraneous and it may mean supplies as in cloth, food, etc.

At any rate, the passage seems to be indicating something like:

Sometimes, the gentry made a power play by failing to provide supplies (goods or money) to the queen in a timely fashion. She was capricious in her dealings with them, no matter what they did.

Elizabeth I was a very astute money manager. When she was feeling broke, or her expenses were genuinely running particularly high, she'd undertake a royal progress, sometimes lasting most of a year, staying with various gentry, who could not turn down a visit from the queen. Apparently, these nobles would curse when word came that Elizabeth was going to pay them a visit--then, they'd put on smiles for the course of her stay with them, although these two-week favors would wreck their own budgets. The "supplies" may refer to the immense baggage trains of royal necessities that the queen took with her when she traveled--and these were, of course, replenished by her hosts at each stop, as she knew they would be. She was very clever in so many ways: these long in-country trips were the first by a British monarch, allowing a goodly sample of the general population to see their ruler.

Thank you guys for your explanation. I really appreciate your help.